I've had the T44 sliders for about a year and they are great, but if you have a 2012+ you do need to relocate the compressor with their supplied bracket. The stock bracket is a chunk of aluminum and the new bracket is steel. For anyone getting these sliders, I would say it is important to get some good adhesive foam or rubber to apply anywhere that articulates with the truck. These are NOT bolted to the side, they are truly bolted to the frame with 2 large bolts and 4 smaller bolts. If you do not apply some foam/rubber, you will get annoying creaking when you accelerate and stop. It has happened to everyone I know who has these sliders, but it is also very easy to remedy.
There are some holes to wash out debris, but I think (and Umberto described this in another thread) you should drop them every once in a while (depending on your off roading) and clean them out, they can get some mud/debris to settle where the compressor sits and cause increased vibration. As for the compressor, there is plenty of air circulation, the rear is actually pretty exposed, which doesn't seem to affect it at all. I did put some foam in that area to protect it a bit more and it works well. I can always take photos, and for El Solis, I can show you in person. Since you raise up the compressor and leave the stock plastic cover on top (the bottom is removed), it does resonate sound more and you will hear the compressor running from inside the cabin. It's not bad at all, but it is noticeable.
These slides are very heavy and you will feel the weight in certain situations - especially if you add more of T44's skid plates (gas or transfer case). The other nice thing about these sliders, because they attach to the frame, you can use them as jacking points, the square nerf bars fit a Hi Lift or other jack perfectly.
Please let me know if you guys have any questions.
Regards, David