i did use tinyXP for a long time and it almost always worked like a charm.
However, those ''optimized'' versions of windows xp were useful back in the days when we had 256MB ram and 1ghz processors, where every spare bit of memory and cpu cycle was important.
With today's computers running 2+gb ram and multicore processors. The performance improvement might be totally unnoticeable.
keep also in mind that, from those tweaked windows versions, some apparently unnecessary windows component that have been removed may actually prove quite necessary.
And it will always happens when your system is all set, meaning configured to your likings, all your software installed, everything working 100%.
2 exemples i went through,
with tinyXP i recently discovered that i coudnt use a remote desktop software called radmin. something in tinyXP has been removed that is required for radmin to run.
with the version called ''performance edition'', essential advanced networking components were removed so it was useless in a business scenario.
i strongly recommend you stick with a regular xp install CD. if you can, switch to xp x64 edition if your cpu supports it, i noticed a immediate performance gain.