30k mile update...
TL;DR version: Buy with confidence.
Still love this set up and think it's great for many of us who use this as a daily driver but still like to get the truck dirty as often as they can. I have a hefty commute so I've done this 30k miles with the Pro Truck lift kit from Eibach in about 1 year's time (I got the "standard" version... I haven't read this whole thread and I know some variations are now out there). My offroading is more forest service roads and some of the Appalachian Mountains... mostly tame stuff and can only think of less than 5 rides where I needed the extra clearance I got from stock. I wish I could venture out and do more, but sadly, life gets in the way.
Again, I'm very satisfied. I'm running XD wheels ($100 a piece on clearance) 17X9 with an aggressive offset, but only stick out less than 1/2 inch from the fender flares, and these are paired with Falken Wildpeak 275s. Even with only the 275s, the aggressive wheels necessitated the BMC. No big deal, my shop did a great job with the pre-fabbed plates and the welding. I also replaced the original UCAs with JBA UCAs. Those things don't like to hold grease in the ball joint, so I have to hit them at least every 5k miles.
My only issue, and I would certainly not say this was caused by the Eibach lift, is that I had to replace the sway bar bushings from the KDSS system. They were shot, and you could feel the clunking from that in every bump, especially in the 10-30mph range. I have no idea if these just wear out normally in a stock set up, or if the geometry changes by lifting the truck caused some quicker wear to those bushings. Regardless, it didn't bother me, although it did take some troubleshooting time to diagnose even though the bushings are in plain sight. The bushings were like $20 a piece and about $150 to replace. I'm a very limited wrencher, so I left that to the experts since you have to strap the system to take tension off it in order to replace those bushings (no thanks). My lift was installed with around 82k miles on the truck and the bushings were replaced at around 104k miles. I'm at 112k miles now.
This was a great set up for me. I get compliments all the time on the lift, wheels, and tires. The on road manners are a huge improvement from stock and it has paired very well with the KDSS (note, I don't have comparisons to make for trucks without KDSS running this set up). Can't wait to hit the 200k mile mark on my truck. Any questions, just ask.