I have a Lumia 925 and I've been comparing it to my 930, in terms of battery life. Now, I've installed the exact same apps, I use the exact same theme/colours/lockscreen/settings, same apps are disabled/enabled for background activity and the phones have been fully charged. The 925 outshines the 930, by at least 5 hours - and this is with glance and double-tap-to-awake activated. Both phones had WIFI and Bluetooth on during this "test".
i had de 925 now got 930. i do the exact same things for about the same time. not a heavy user. and for me the 930 is better than 925, with the 925 i took it off the plug at about 10,30 am and at 1,00 am i used to have a bit more than 50%, with this baby at the same time i got more than 70%. the thing is that the 930 is much better on standby. but if you are a heavy user you should get the 1520... i'm very happy with my 930. go for it