Thanks for the llink. Right now the factory roll bar/sport bar attaches to the body which is in turn attached to the frame with rubber mounts (or some kind of flexible mount). Kentrol's tie-in looks like metal to metal to metal. Where's the flex? Or is that not an issue?
Frame flex is not an issue for a short wheel base, especially if you have good articulation. When you tie it to the frame it becomes a roll bar, instead of a 'sport bar'. Although the Jeep bars are designed to work, a frame mounted bar is safer, especially at higher speeds.
Redtail, I would most definately tie in to the frame w/a glass tub. The tie in kit works great, but does require grinding/welding.
You'll probably here a lot of pro's and con's rgarding frame flex, IMO if you have articulation, the stiffer the frame the better.