Don't ask me, the version I have doesn't even have the gecko option. I just treat it as an improved version of IE. Whenever I need to check a page to see how it looks in IE, I fire up MyIE2. I never use plain IE at all, and I never use MyIE2 (or any other such frontend (such as avant (formerly operaIE or IEopera or some such), crazy browser, or inet tabs)) except when I need to check a page.
For me, it's between firebird (the previous version of firefox) and k-meleon. Firebird/fox has more features, but k-meleon is faster. I also like the fact that k-meleon can read/write IE favorites, mozilla bookmarks, and opera hotlist.