I own an 820 and love it, but I'm selling it because despite the bad press, the 625 is a great phone. Yes, the screen is inferior, but you can tweak in the settings to 'bring it to life'. Battery life is absolutely superb. The lack of Glance was a concern.....at first. I don't miss it at all. Sound quality 'slightly' inferior but not enough to lose sleep over. I'm not too worried about losing wireless charging either. USB charging is much faster, and as battery life is SO good on the 625, I'll be charging less anyway
All I ever read on the 625 was 'terrible screen and bad viewing angles'. Total rubbish. Admittedly, it's no 820 screen, but it's better (to me) than the 620 screen.
If you are one who wants the best model with bells and whistles, you'll overlook the 820 anyway, but if you want a solid fast Lumia, the 625 is well worth a look. All the apps I used regularly on the 820 run perfectly on the 625, so the 512mb RAM vs 1Gig Ram doesn't affect me one bit. In a week of side by side comparison, I have yet to notice ANY difference in performance between the two phones. I don't even miss the lights on the three function keys. Granted, I can understand why some would....
The 625 and the 820 are both excellent phones, and I would imagine you will be equally happy with either
Same experience on either phone with amazing battery life in favour of the 625