10MB doesn't sound like a lot at all, either. They are responsible for pretty much everything that happens on the system, and it is perfectly normal for them to read and write to the hard drive without the user having initiated it.
Which describes probably 50% of the users out there in the real world. Hello, There are a number of Svchost.exe running on a Windows system, and they are made up of one or more of Microsoft services. You're not going to get much responsiveness on a 5yr old celeron w/2gb ram and Win XP while you're downloading a game, watching youtube and the A/V suite scans your computer in the background, and there's 5 other people all sharing your 10Mbps network.
The speed of a browser can also be affected by other factors like the speed of your connection, how many devices are on your network, what tasks your doing on the computer at the same time like gaming, downloading, streaming movies (netflix, hulu), and your hardware. I use Firefox 95% of the time at home with adblock+, if I encounter an issue I clear cache, if it still has issues I switch to IE 10, usually this is all I need to do but once in a while IE has problems with a page and I just move on to something else. But in the end they all take me to the same place. Sure some load pages faster than others, and some have issues with certain pages.
I've never really noticed a difference in browsers speed wise.
