From memory, sorry couldn't quickly find the comparative bench, but the software raid from Apple isn't bad at all, was doing a little worst but not that much compare to some hardware raid.
The only problem (not sure if they fixed it in the past few OS, I haven't need a RAID in quiet some time), is the boot drive shouldn't be on a RAID drive. You may want to check this back to ensure this is possible with the Apple RAID or the other software RAID.
Hardware RAID is always the best solution but cost more. I wouldn't use the other unless they can show some bench mark of the difference of there raid solution. Take into account the R/W speed and also the CPU usage for running those RAID. A RAID that would eat a lot of CPU to increase a little on the HD performance isn't that great, depends on your need.