As I mentioned, hardware is not the issue. My only concern is new features and updates. Today I bought Lumia 720 for my gf and we like it very much. It's fast enough, very good looking, good materials. And I'm very much leaning towards buying one for myself. Mainly because the battery on 720 is much much better.
You and some other users mentioned a very good point in this discussion - 512MB RAM WP phones are very popular among WP users. So it would make a lot of sense for MS and Nokia to not leave us without any major updates and features in the future. That kind of calms me down
You and some other users mentioned a very good point in this discussion - 512MB RAM WP phones are very popular among WP users. So it would make a lot of sense for MS and Nokia to not leave us without any major updates and features in the future. That kind of calms me down
You can only answer the question from the 1G v 512MB perspective given your questions criteria.
By that count, 1GB (with faster CPU) will run everything released for a while - all games etc. So 820 is better.
Looking at hardware, I'd honestly consider the 720 over the 820 because it has a longer battery life, arguably better camera (FFC for sure), and with so many 512MB phones on the market, games will be made to run on a 512MB device eventually, if not on day 1.