You make good points about both Treyarch and IW. They do both have their own special flavor with their games. Unfortunately, Activision is more concerned with putting out a new game every year instead building a top notch game that they can support for 2 years via great content download. I personally prefer the people who play and the style of play that BF offers, but odds are that I will pick up MW3 to play occasionally when I need a fix of kicking peoples ass in a high paced MP online.
The streaks look a bit ridiculous, and even though the Support Streaks won't stack up to a lot of kills for the person getting them, it will greatly tip the scales in favor of the team that the person is getting the Support Streaks for.
I'm still a bit worried, but seriously, what are the alternatives? I will most likely pick up MW3 as well because I'd like to play the campaign, but as far as online MP is concerned there are only 2 real possibilities. I'm just hoping that BF3 is the one I like best because the new killstreak/perks system in place with MW3 looks like it rewards players for EVERYTHING and you know it's going to be complete chaos.
I'm going to keep my pre-order active until I make my decision, but odds are that I will rent the game before I make my final decision. I quit playing games back in February and I would be highly displeased if the first game that I dropped $60 on wasn't what I expected. In the meantime, I'm going to give the "beta" a chance and maybe it will grow on me. I don't know why, but I simply don't like the feel of the game.