Battery life on the pro is excellent, I get about ten hrs(brightness usually halfway)
Now CHARGING the battery on the other hand.....Jesus Christ, get yourself the USC-C cable and adaptor, If you just charge it overnight that's fine you won't notice of course but theres going to be times when that isn't an option and it's going to be incredibly frustrating
I don't have a 7 but there's nothing slow about the pro, it's a fantastic device, only other complaint I'd have (and it's nothing you won't have heard before) is the ridiculous waste of screen space, in fairness though once your browsing websites or watching movies or whatever that won't matter but when you see your home page with the blown up apps and huge gaps between them it is a bit annoying and just not taking advantage of the device......I'd consider it a miner complaint though really