It is lightening fast and has got some great intended functionality in security, privacy, cookie mgmt, multiple pages open, online dictionary, source viewing, multi-platform support, etc, But...it's a bit buggy yet...but worth a free download....
I paid for it, and I was pleased with 6.01, upgraded to 6.03 which seems worse (ignores link history after restart), I'll upgrade to 6.04 this weekend.
My biggest 3 peeves:
1) cookie filtering not working quite right
2) bookmark mgmt almost non-existant
3) seems to have memory leaks which catch up after about 2 weeks solid heavy use.
There are a couple freebies Book Mark Priest and Opera File Explorer which make things tolerable.
Book Mark Priest lets you convert bookmarks between IE, NN, and Opera....so you can them all in-sync (assuming one browser always has a master copy - there is no sort/merge capability, just convert enmasse.