you do know that you are less protected now?
any software that no longer works on SP2 or SP3, simply uses features, that are no longer used/available, or were using hacks to get the stuff working...
If the software itself is old: try upgrading that too....
and why inferiour? because of vista? because i had more system crashes /w xp sp1 then with xp sp2 or even xp sp3....
and the only crashes i had on my windows 2008 server (yeah legit ), was cuz of a faulty intel nic driver :/, yet latest windows update found a new driver and fixed it (it fixed the BSOD on my other 2003 server box too )