What is the MOST reliable AR Pistol Buffer Kit?

[ENTHUSIAST]

I was looking at an ACE buffer tube kit...

http://riflestocks.com/catalog/product_info.php?cPath=75_79&products_id=187

I heard since they use a CAR weight and spring they cycle with more reliability than a "shorty" AR pistol buffer kit...

Also, who else makes the MOST reliable AR Pistol buffer kits?


THANK YOU,