I may be wrong, but I believe that the powered SVS subs have a limiter built in to the plate amp. I've heard an unlimited SVS botom and IMO limiting is sensible.
If you mean Bass Peak Level Limiter, then I WAS using it on my Onkyo 989. I quit after reading SVS-Ron's post about bass compression when using BPLLs. I don't know that I ever noticed a problem due to using the limiter, but had engaged the BPLL just to protect the driver in case I got over enthusiastic with the spls.
Now that I've upgraded to the CSi driver, I'm not even worried about it!
I've also read what Philip mentioned about the PC series. So the limiter probably only would be applicable to the CS line.