Last winter, I pulled my interior to better insulate my interior ahead of doing a Classic Air install. Since I had it all out, and needed to insulate the roof/headliner area, I took the dive on the TMI one-piece. I like it, it does hug the roof line and offer added headroom. It also looks good (not stock obviously) but I have no regrets.
Definitely have a helper - it was a bitch wrangling that thing into place by myself, but still possible. The pre-cut holes for the visors and the overhead cabin light were well placed. In fact, I found that the easiest way to align the headliner was to use the screw holes for the light. I put a couple small screws in the dome light holes to hold the headliner in place as I worked my way around and drilled holes for the seat belt anchors and visors. I also kept my existing sail panels, I did not need to entirely remove the old ones. Hope that helps.