Count me in the FF 'like' group - so much so that I use the beta version and report problems/enhancements: which, I must say, are very minimal. I've only found one site in my limited world of Web interest that has problems with FF and not another browser.

Regarding taking a long time to load? I find that more a function of a whole lot of other environment variables, like network speed. For me, I haven't found any unexpected payloads using FF, but I do keep my security settings pretty tight.