With a vast lack of experience in this area, I must admit to being pleasantly surprised at the ease of use my Promise ATA-100 cards have provided. I only ever use them for very basic stuff - essentially plugging lots of different drives into when I want to partition, erase, or test, but they work just fine.
I have owned just two of them: the first was bought, at Buck's suggestion I think it was, to pop into my elderly 6x86MX board that we use for testing hard drives after the 32GB BIOS limit in that board started to become difficult to live with.
Mostly they just work under DOS or 98 in DOS mode, but we sometimes do full installs with them, though never actually bothering to load any drivers. So the finer points of software compatibility are something I can't comment on. As for the hardware side though, so long as it's a hard drive that I plug in and not one of the unsupported other IDE devices (such as optical drives, which you probably need the drivers for), they work with everything and anything.
The second one I bought because to plug the first one into that particular ... ahh ... system ... I pulled the metal mounting bracket off it. And then one day, against my better judgement, I borrowed it to test some stupid box of pox that was in the workshop for repair or testing, and essentially being an extrememely stupid and careless sort of person, and not having the bracket to remind me of the correct orientation, I plugged it in backwards. So I had to buy another one.
Then I thought - oh well, WTF? I'll send it off and see if they laugh and tell me where to stick it, or maybe replace it. They replaced it, so then I had two. :wink: I did feel a moment's guilt over that, but decided it could be my small blow for justice, freedom, and revenge on behalf of Santilli.