I'm currently rolling with one of these. The only reason is because I got it for ~1/2 price (around $70 CDN when list price was $135). I would never have paid full price for this thing. Or, well, I might have paid full price for this thing and felt ripped off and returned it. I had to return it twice anyway to get one that wasn't constantly triggering the thumb scroll wheel events.
Anyway, the battery life seems fine. It has an LED battery life indicator on it that goes red when it's low, so it's kind of hard to really have issues. I would certainly not use it as a travel mouse or laptop mouse or anything. On that count, what I DO have an issue with with this mouse is the problems getting the charging contacts to contact. It has it's good days and bad days -- some days I've had to put a pile of books beside it, with one sitting ontop of it to keep it pressed down so the contacts make contact so it would charge.
I don't see any acceleration issues, but I tend to acclimatize myself to a given mouse setup within a few days. If I start worrying about acceleration, I'm going to be infront of my computer for
hours on end trying to convince myself that it's either accelerating or not accelerating. (FWIW, acceleration is about speed of movement -- the speed of the physical movement of the mouse has a non-linear relationship with the speed of the cursor. (I'd assume quadratic, but testing these things to that level of detail is almost impossible without a robot -- although a mock usb device module in Linux might work to test if Xorg is doing the accelerating.... hrm.... but that wouldn't test for hardware acceleration anyway)).
If you TRULY hate acceleration, then get a tablet and use the mouse on that -- I will break out my old Graphire tablet if I'm getting sensitive to acceleration. It's usually enough to remind me that I don't hate acceleration that much.