Yes, I use Ibrowse 2.3/OS3.9 on my A4000/060 :-)
I mostly use it for GMail/Google, Amiga.org, Amiga.dk, Aminet & Jabberwockey/MSN.
Of course a lot of text editing, a little gaming and so on..
I do have Mozilla Firefox 3.0.1 on my XP box... But the Amiga is just so much more fun to use :-D
AND! A big advantage, the Amiga does NOT get all the malware there are on the net. I surf without protection, with my Amiga.
On the PC some kind of virus/malware protection is absolutely necessary!