I assume that for every person posting to this and other boards with IE 6 problems, there are 1000, 10000 or 100000 people who aren't having any problems with it.
If you've got an up to date system with XP there may be some features in IE 6 that you need to get the best out of that system. Like you might need Direct X 9 if you have a fast computer for game playing.
At least it is to be hoped that IE 6 fixes some of the well known and longstanding security holes in earlier versions. Check this out;
http://www.hevanet.com/peace/microsoft.htm (19 unfixed vulnerabilities as at Dec 2002)
For myself, I prefer to place my security in the hands of third party software, including an ISP that uses a modified IE, and assorted anti virus, anti trojan and anti spyware tools.
My old, slow Win 98 machine chugs along quite nicely on IE 5.5 SP2.