[blue_skies]

Yes, I think the Onyx has a lot more note-taking (and saving) functionality. It depends what's important to you and if you don't mind the extra cost.

When I ordered the Mimas, it still wasn't clear if/when Onyx would release a 10 inch note-taking ereader, and I didn't want to wait any longer. The Mimas was a lot cheaper and I have had good reliability with the other smaller Boyue device I bought several years ago. The screens are very nice on both of them, and have perfect frontlighting, which is not something I can say for the Kindle Paperwhites I tried.

I occasionally feel a bit regretful that I didn't wait for the Onyx, only because the software is more polished... but then I remind myself of the things I do like about the Mimas, including the lower price and months of extra use I've gotten by not having to wait, and I don't feel so bad.

Personally, I don't think I would sell my Mimas and buy the Onyx because I love having the hardware buttons. (The speakers too -- I'm not sure if the Onyx ended up including speakers.)

I am probably an atypical user in that I use the Mimas to help alleviate my insomnia. Being able to use the device at bedtime (with the warm amber light) to make any notes about things that would otherwise keep me awake, read a bit until I'm sleepy, and then use the built-in speakers to listen to a meditation recording that is like audible-ambien... has been incredibly helpful for me. (As I'm dosing off, listening to a recording... it's easy to reach the hardware buttons that control the sound volume. I find that so helpful since I often have to adjust the sound... and I don't even have to open the cover to do that with the Mimas.)

So, if you are just a casual at home user like me, you may find the software if good enough and enjoy using it.

However, if you want to use it for school or work, or more complex, rigorous note-taking... you would probably be much happier with the more expensive Onyx.