So first lets address the DRM issue. Whichever mobipocket device you buy will have a unique serial number. Any files that you currently have downloaded will
not be coded to that serial number and will not be readable on a new device.
Instead, you will need to go back to your original source/store and input the new device number and redownload the books. So the first issue is you won't be able to access the books unless you can also access the original store and your account that you bought them on. If for some reason you can not access the original store/account you will either lose access to the books, or you must remove the copy protection if that is legal where you live.
In regards to reading protected .mobi your choice has become quite limited among e-ink devices. The Cybook is the only one that I am currently sure supports it. I know that the Hanlin V5 did, but I'm not so sure anymore. Mobipocket (Amazon) has a new rule that devices are not allowed to read both protected Mobipocket format and other protected formats. As a result, most companies have chosen to support only one protected format and support for protected MP is disappearing. You should still be able to read protected MP on you desktop PC and on any platform (smartphones) that can install the mobipocket mobile reader.
On to the specific devices you mentioned. Breaking screens are a problem with all of them, not just the Bookeen. These things are lightweight and we tend to treat them to casually. They get fumbled, dropped, and otherwise mishandled. In terms of fragility think of them like a laptop. A laptop can and should last for years. However, you are probably pretty careful about caring for yours. That's fine advice since I've broken one (uh, maybe two
) myself.
I personally am not a fan of the Cybook. It was one of the earliest e-ink devices available and I owned one. If my choice was the Cybook or nothing I would gladly choose the Cybook. However, today I think there are other devices that work better. I know that there are others here that still love their Cybooks, so these may be fighting words
. Then again, that may leave you without a way to access your protected content. If you are not able to strip DRM; if you have a large investment in protected files; and if you are willing to put up with slow startup times and occasional (daily?) restarts then this may be your only choice. As I said earlier, if the Cybook was my only choice I would go for it.
If you are legally allowed to remove DRM in Canada and are willing to do so, then format is no longer a barrier. It is no harder to shift formats than it is to remove DRM.
The Sony would require a format shift. From all reports it is a fine device -- I don't have one.
Right now, I am partial to the Astak EZreader Pocket Pro. It is a smaller (5") device that I feel will combine portability and usefulness. It is also fairly feature-rich. However, I suspect that you need to be comfortable with risk if you choose this item. Only a few people have these in hand yet, and we don't have a full set of reports yet. A couple of people are concerned about the time it takes to turn a page. Its not clear what is going on here yet since everyone isn't reporting this. Even if it's slow I think it will be acceptable for me. The pocket pro is also among the cheapest units at $199 from Astak.
So, either take the plunge and purchase Astak, wait a few weeks to hear more reports, or go with the Sony. Frankly, the Sony may be the best choice. It is a solid unit with a good reputation from a name brand company. If protected mobipocket is a must-have go Cybook if you are willing to live with its bugs.