Here is my 06 Titan KC XE with a Thule XSporter rack. I know there has not been much posted on the XSporter so I thought I would talk a little about my experience with it.
Well I bought the Thule Xsporter off of Amazon.com for $390 free ship and no tax which was awesome. it is a very well made piece equipment. The welds all look nicely done and the rack seems quite sturdy for being aluminum. I purchase the Thule Hull-a-port attachment from REI ($120) for a Kayak I was planning to buy at the time. This rack is great for all the XE owners out there that didnt have a sliding track system from the factory. The rack is adjustable and locking (by key) for two heights (above and below roof line). When not hauling the kayak I always roll with the rack at the lowest position to minimize airflow turbulence. The rack installed onto the truck smoothly except for my dumb a** cross treading one of the bolts. Had to call Thule for another bolt which took forever since they were on backorder for all XSporter racks.
Lets jump right into the problem areas:
There are two clamps for each base of the rack which was great. But the clamps are basically just bolts that tighten down on some aluminum brackets pinching the sheet metal and plastic trim of the bed between your rack base and the brackets. When you tighten down the bolts onto the brackets, the brackets tend to walk on you (which is quite annoying). And now since your torquing down stainless steel bolts to aluminum brackets, you get shaved aluminum all over the place since the brackets are softer than the bolts. Now the brackets and the bases all hold firmly but it just seems like it would of been a better idea if they just designed the brackets to be integrated with the bolts somehow, or just use steel instead of aluminum for brackets.
Like I said the rack is quite sturdy but the the Titan's sheet metal is not so. When raising and lowering of the rack, I get a wobble that is clearly coming from sheet metal flex. Once everything is locked at its low or high height it the rack is sturdy with little movement.
Since the based and clamps pinch down on the sheet metal and plastic trim, it appears to bend the plastic a bit out of shape. It would seem that in the long run it would warp the plastic. But I figure its the price to pay to haul around my toys. Besides I can just purchase new trim when I want to take the racks off, if I ever do.
One last negative thing about the rack. The rack also had a howl when set at the high position. This seems to be due to the track on the rails for accessories. It is getting the effect you would have by blowing across the top of a beer bottle. Now the rack does include rubber trim that is suppose to be inserted into the track. I just have been lazy, and never installed it.
Now I put out all the bad things about the rack, but if you really want to haul a kayak or some bikes and still use the entire bed for gear, I feel this is the best way to go. I didn't want to deal with a trailer so as far as I saw it this was my only option to haul a Kayak or canoe. Overall the quality is good, it is functional, there are a ton of attachments for your outdoor outfitting needs, and it doesn't look half bad IMHO.
Here are some pics from this last weekend:

BTW the boat is a Wilderness System Tarpon 130T (13ft) and my Titan is a bone stock XE 2WD with OR wheels. I don't have to tell you guys how bad a** the truck is.