iOS 5 doesn't seem too bad on a 3GS (my boss and brother-in-law have one), but then again, I lived through the iOS 4 on the 3G debacle. I have never seen a device so crippled in my life. They fixed a number of the issues with 4.1, but those first few weeks were horrendous.
I recently used the old 3G as a travel phone in the UK... brought back some memories.
