We are now entering the "people dont know how stuff works - but still try to make sense of it" phase. You can identify it by different people throwing stuff out and seeing what sticks.
Here is a rundown to give you a little indication of how stuff works.
Android on the Mars is plain Android - you can "do all things Android" with this device, there is nothing holding you back (despite root currently not being available).
Here are the limitations and why they are implemented.
Task killer, on all apps per default. Thats a chinese manufactuers darling - whenever they "think" that they need better batterylife, they put in a task killer set to aggressive. Its mostly idiotic - it doesnt hurt "much" though - so let them do it. At least they allow you to whitelist apps that you dont want to be killed in the background thats commendable, because most do not.
If the SOC doest have any major flaws while entering hibernation, its mostly a useless thing to do - but hey, for some reason its on the top 3 list of modifications to android chinese brands like to implement.
Best rational for it I could come up with - there are some notorious applications that like to prevent your android device from hibernating, such as facebook. When chinese manufacturer puts in taskkiller those get shut down. Joe Smoe sees better batterylife (sees not - not realtime notifications, because that stuff usually messes with GCM), posts better testimonial on social, chinese manufacturer makes more sales.
Now, you can whitelist apps you want not be be killed regularly, those then work fine and as expected.
With the little tweak menitoned by another user (auto turn Wifi off in standby), this device not only performs like a normal Android device, it also has about the standby time of a norma Android device (around 5 days with with an infrequent (mostly stand by) usage pattern).
Nothing exciting yet. Nothing too problematic either.
The usage detriments come from the eInk side of the occasion. And they are understandable. In most apps they dont fully refresh the screen that much (general pattern seems to be about one full refresh every 2 minutes), so in most apps you have washed out lines eventually. Not heavily washed out, and by no means unreadable, but noticeably worse - than the optimum.
This is also all very understandable. If you know, or have written the app in use, you can optimize full screen refreshes (f.e. native reading app), and everythings hunky dory, if you dont - you go with a middle of the road setting, that also optimizes a little on responsiveness - as you want android apps to be usable. You make a compromise readability suffers.
To their defense, they at least tried to give you controls to alter picture contrast - and in some (few) apps they actually work (comixology), on most though they dont. Or they work for the first refresh upon app launch - and then revert to default
Thats not too bad in general, because you can compensate by using image viewers like Perfect Viewer, that can alter image contrast on their own, or you can use reading apps that alter font contrast, or you can use certain fonts with a kerning "optimized for eInk". And in the case of comixology - at least I lucked out and the "custom greyscale settings" the Mars allows you to set "took".
In general - deactivate "animations" on pageturn, to get more contrast out of the same settings (I have animations turned on both on Perfect Viewer and in Comixology - because I could use other means to make the image more "contrasty").
The ONLY way out of this dilemma would be, that the manufacturer of the eInk device looks at different apps individually, and optiizes screen refresh behavior depending on what they are doing. Thats probably cost prohibitive, so thats also not something you could reasonably expect. Also it would produce 5000 "could you do for my favourite app?" requests in a week (because people usually demand stuff, without knowing if it is feasible), so even if you are doing that with certain apps, better tell no one.
Web browsing as a daily usage scenario is out anyhow - because eink is still too slow to make that a pleasent experience (A2 mode (only use half refresh time) is a nice trick (and actually more than a marketing gag) - but even then - meh).
If you'd want to judge this as an Android device, its till incredibly slow and unresponsive - THA EIGHT COR PROCESSOR, hasnt solve that. But then people get so excited, when they hear PR talk...
That this thing "comes" with the google play store also one of those "dumb user" concessions. Not because its not much more convenient (it is), but the reason, why it doest do so "by default" without "changing that odd "setting"" are license agreements, that woudl make the device more expensive for the manufacturer to sell. Then everyone and their mom complains, that google play services and the play store cant be installed - then the manufacturer tries to go with a legal loophole solution, that probably wouldnt hold up, If google even recognized them as a vendor and noticed. If you are selling your device with the google services framework active, you are entering in a licensing deal with google. Not to ship with that active by default is no "oversight", its what their lawyers suggested.
Questions?
"But not the freedom of real adroid--" > No, its real android. Fully featured, fully functionable.
"But maybe that other manufacturer will make better Android eInk tablet!" > I doubt it. Most issues are structural.
"But what tip, so I can browse web more better" > None, because thrid party apps and perfect screen refreshes on multimedia content, that could be text, a video, or a gif - on one screen - isnt feasable
"They made the mistake to not go with Play Store in the beginning" > No, thats actually them trying not having to adher to googles licensing terms. And then they buckled, because the average consumer demanded it and fabricated, a probably still illegal workaround.
"But standby battery usage is so worse and I had to intall abttery saferrr" > You just stuck in the "believes everything - didnt test anything, goes whats advertised" phase. Its normal, that after every firmware update of any smartphone manufacturer, you get 10% my battery life so much worse, reactions, that are purely confirmation bias. In case you havent noticed, most people cant set up standardized test scenarios. They rather read horoscopes and play the lottery.
"But fastest, and octacore, and A2 mode!" > Just forget it. Its usable. As a multimedia or webbrowsing device its still a crudge though. eink being the limeting factor.
"I wonder what "brand" will release in response to Likebook Mars" > Nothing, because the eink based android device - isnt even a category. Its what some manufacturers do, because they can use android for free, and by now have specifications for a few chips that can run it. Up to 6.0 also with eink support (afaik thats thanks too google as well). Having an Android eink device, is an interesting middle ground. With its own pros and cons.
No sane "big brand" manufacturer would go with an Android OS and a corresponding SOC at this point. SOCs too expensive, 1 month batterylife marketing keypoint not reachable, licensing quarrels with google, not being able to brand this as your own store frontend, ...
"They use a taskkiller! Its not normal android!" > You can define exceptions, they work, thats the important part. Get over it.
Yes I agree it is silly. But they are angling for positive word of mouth by people that are impressed, that their facebook doesnt always have to be running in the background. People that have reached the next level of evolution and wont even install it - get no discernible benefit. But also hardly any detriments. (Havent checked if GCM real time notifications work, could be broken. But its an eReader not your phone... Chances are you'll get over it. Apart from that its fully fledged android.)