Online looks to be like the biggest difference, Gears was 4 vs 4, Gears 2 supports 5 vs 5, Resistance 2 is 30 vs 30 (6 squads each team). People say this mode is well done and lag free, can't wait to try this and 8 player co-op out myself. 
Seems they have implemented the same crouched running as they did in Gears 1, as a physical therapist I dislike it as it's very unrealistic to me. I've mainly seen the ending of Gears 2, that part seems very disappointing to me, similar as the first game's ending wasn't a highlight. Same bad acting juicing bodybuilding space marines overall it seems as well... I can however see why this game may appeal to other people, but I'm more the Half-Life / Resistance type of person myself.







