battery on the 925 is bad. it doesn't even last a day on average use. i use 3G internet occasionally, rest times 2G connection for calls/sms. play games like angry birds, cut the rope for about an hour. moderate IM (whatsapp, hike) and facebook (from app), and a little web browsing. sometimes music via headset. it doesn't last longer than 7-8 hours. two things that drain the battery like hell are mobile data connection and (unfortunately) the screen. MS should seriously provide proper brightness control over screen. they are mostly too bright just for the sake of outdoor visibility, but drain battery and strain the user's eyes.
besides this, you get a longer Nokia Music subscription, HERE Drive+ (lifetime international navigation and offline maps) and more apps (due to 1GB RAM). and obviously a much more sexy-bodied phone!
i do have a tip though. avoid listening to Nokia Music songs over loudspeaker. their bitrate is too low and it causes speaker distortion at times, and prolonged usage can damage your speaker. my loudspeaker distorts a lot!
and ya, since it has a samsung made amoled screen, you'll see black patches when you use the phone in the dark. they totally kill the display's beauty, but you gotta live with it.
and also, there is a firmware bug that causes the display to flicker when you turn on battery saver brightness in display settings and put phone on battery saver mode.
other than these, there is also a bug that causes the network to freeze sometimes in poor connectivity zones. and you have to go in offline mode and back online to get the network working again.
the camera is a huge plus. amazing picture and video quality. screen is comfortable to use.
hope this was helpful.