Thanks to everyone for the responses so far. At this point, after reading posts in this thread, reading other threads, and lots of YouTube videos I'm leaning heavily towards the Retrax Pro MX. The capability to lock it shut, the fact that its sturdy aluminum, and the fact that I can open it varying amounts will be a big advantage for my uses. It seems to sit very low profile and doesn't look like some slapped on aftermarket part. It has a nice factory look. The biggest downside is that I lose a foot of bedspace but, then again, I haven't ever hauled anything in the bed of my raptor that was big enough to require the extra foot - and if I did, it would be a rare occurence. I've also only a few accounts of the Retrax leaking.