I added one on mine this season. I wasn't having running issues prior, but felt the PCV was worth the extra piece of mind. Sled feels much better than stock.
Rocket is correct that for some reason these sleds are not all the same. However, they are all lean through the mid range RPM's. Most people love the improvement, but I have read of a couple people that aren't having much luck with them.
The HP gain is better than a pipe and you will improve the longivity of the motor by fueling it properly. Failure still lies within your ability to tune properly. On the average the SLP and Dynotech maps have been working good for most applications.