I've heard great things about both but have never had one myself. Personally I have only needed one in deep sand situations. I would highly recommend having your suspension dialed in professionally and then fine tuned on the trail. Once you get it perfect you will not be all over the place and therefore you will not need a dampener. Your buddy will appreciate it as well because you'll stick your line instead of bouncing into his with dampened steering. Unfortunately it takes a couple of hours, riding the same section of trail, to get it right.
1970 FJ40- TBA