I had the same dilemma...S60 has improved speed lately but it still has a long way to go before it can have S40 kind of speed....my new E61 is much faster than my old 6670 but still not as fast as 6233.....In the end, S60's vast software pool won me over to stay with S60...I was just about to buy 6233 when I got a good deal on E61 and its Wi-Fi coupled with S60 made me stay in the family
Another thing is the multi-tasking...I think even in 6233 you can't play music and do other things (search your contacts/ or SMS) TOGETHER...(I might be wrong so wait for others to comment)
