Im using Vista Ultimate 64 SP1 and personal experience nako, with the issues you mentioned CS3 is faster for me probably due to superfetch, it hasnt crashed ever, no crash in firefox aswell. Only had a few beta utilities that stopped working.
I can see the filters not working as a pain in the butt though.
The HP printer being not supported and limited is the biggest issue here if its that important. Going back to XP might be the best thing to do for now.
Also I would suggest to buy additional ram nlng 3-4gb instead of using readyboost. Its good for computers with 512mb RAM - 1gb, but loses its effectiveness if taas na imo RAM.