TreyArchs cod's are the better cods imho. IW had a great run with CoD4, MW2, but then 3 came and it went to hell. Lag Compensation, Not yet Nerfed PP90M1. Camping Degenerates -ELPRESADOR and finally Noob Tubing. I found that MW2 and 3 both encourage this type of play. Which essentially sucks, because I enjoy gun on gun confrontation. I don't need to hide in a storage room, behind a barrel, proned under a tree. I run around and kill. I die sure, but Idc. I kill as many as possible before it happens. And in games like blackops it's easier to find because not as many people run around noob tubing the map or quickscoping every five secs with interventions.
I will state it now, I'm in no way saying cod doesn't have it's share of scrubby players. But TreyArchs cod's seem to have the better communitys. People that I've played when not abusing ghost and a famas/ghalil. Are actually motivated and trying to run around for kills. I just find the community more enjoyable. IW's games are good and fun sometimes won't deny that. But MW3 is what really turned me away from their games. I know it's sledgehammer and IW is gone. But they could of used the MW2 engine for 3 since it was the final game of its series. Just my 2 cents...
And to answer your first question. I've already pre-ordered. This game will be a fun sequel. It's look is what has some fans angry. But look how well people enjoyed Red Dead Redepmtion after it went Open world after the previous Red Dead Revolver which was Linear. Sure it will have it's angry crowd, but when the game ships and people play it. I'm sure those who hated it for the time being will grow to love it. It's CoD for a reason. It's a love hate relationship to the series at times, and it's why the franchise has gone on to sell so many games. It sucks you in lol.