@Aaron Stone
I've tried several options (including FBReader last night -which hasn't had a Windows release since 2010, FYI) and ADE still has the best features and displays the best (and has easier controls), IMHO.
I don't see much point in changing things once they get to a point where they work well, so a long time since a new release isn't an issue for me.
I use FBReader on both a tablet and my desktop, and I also use the E-book viewer that comes with Calibre on my desktop. And I find them both do a perfect job of providing a readable text screen in which I can adjust the font size and on the desktop I can adjust the window size. Both are very easy to customise to suit the user. Personally, I can't see anything else in the way of an e-book reader that you could want as you can change the font, font size, display format, rotation, colours, etc in both of them.
I use Calibre to create e-pubs and not as a library manager, so I've not investigated it's capabilities in that area.
I looked at trialling ADE to see what's it's like, but since they do not make it available from their webpage I decided against it. They do have links to send you off to the Crappy store and the GarglePray store so they can get a lot of information on you and track you better, but I don't have an account with either and I have no intention of starting an account with either. Thus I didn't investigate ADE any further. The Adobe site didn't give and easy indication as to whether it was free or you paid for it, and I see nothing on what I can see of their site that they offer anything that Calibre doesn't offer.
Oh, just found something on their site which lets me know ADE is a waste of time for me as it does not support Linux or Unix other than Mac and Android. While Calibre and FBReader support all platforms.