I almost always have under 10-20+ tabs open.<p>I tried to use chrome but it always cries "Oh snap.." and all the tabs crap out (so much for individual). Firefox slows to a crawl, Safari and IE on windows both aren't even worth opening 1 tab in. So I stick with opera. It does the best overall job for lots of tabs. Although it takes quite a bit of memory..<p>With that said I really notice a lot of slowness on sites that use embedded fonts, more so then anything else. Next is flash, if I block flash from running my browser really speeds up. However Javascript has been replacing EVERYTHING. Even when it shouldn't it does, and is required by many sites, so I cannot turn it off, and some sites use a lot of resources for this mostly pointless js.