Whats the diff between w2k software raid and using those cheap promise or HPT raids?

[RichieZ]

I mean both are software based, is the only difference that w2k software raid needs to have dynamic partitions? I have a 10K RPM SCSI boot drive and I will probably get a real raid controller for IDE (escalade or adaptec). If I have a raid card w/ its own processor and local cache will I get the almost no cpu cycle usage of SCSI?