Just picked up an HD+ yesterday, and I am really enjoying it so far. I was tempted to try and root it so I could sideload Amazon Video and Google Play. But I bricked a $250 Nook Tablet almost exactly a year ago, trying to do the same. (well, back then I wanted Kindle and Comixology) I am clearly not to be trusted, so I think I will run this one stock for a bit.
I loaded about 150 epubs on it, to go with my 35 or so B&N purchases. You have to sort into shelves one at a time, but it didn't take me that long. Reading is a pleasure, including one persnickety PDF I accidentally bought from Kobo. It displays comics as CBZ very nicely, though for the first time I would be okay if they were PDF, too. I loaded a few low quality MP4 videos, and it played those well. Haven't tried a larger, HD quality mp4 yet -- I suspect it will be aces.
Dropbox and Goodreads work great. It even streams my dropbox-stored videos, something my iPhone 4S will only do for 15 min a file. (It might only be 15 min, but it didn't warn me of that fact the way the iOS app did.)
Went back to B&N today and bought a cover. The thing's def a fingerprint magnet. If I had it to do over, I would have paid a few extra bucks for a "designer" cover with cloth rather than the basic vinyl-like one I got.