My experience, Chrome starts out very fast then goes down over time. Firefox keeps going strong, year after year. One thing I don't do is load up toolbars and a ton of extensions. Drives me crazy when I get a computer from someone and it's got a lot of programs running in the background, two or three IM's running and toolbars an inch thick at the top with no current security or firewall install to help control the beast.
Just keep it simple. Chrome or Firefox will do fine IF you follow the other ideas.
I would use Firefox, I have chrome also and tried to use it but i think Firefox is alot better. I also looked up on youtube how to make it faster and did that also, I dont know if you can do that with chrome.
I tried Chrome, but I have used Firefox so long now it is hard to switch to something different. I thought Chrome would be faster, but I couldn't tell the difference. So, I'm sticking with Firefox until something else really impresses me.