I sold mine, and I only had it bagged since last March, but I guess I could relay my experience with bags...
You have to set it at ride height, get it aligned and maintain that ride height every time you drive it any distance. The alignment changes drastically when you raise and lower it, so the ride height pressure is very important to keep from wearing your tires. I had my tires since 1000 miles and I sold it at 16000 miles and they were still almost like new. (I guess that says that I took care of the alignment)
Also, you hear all the time about fellas blowing bags or something. Sure it's going to happen eventually - they're rubber and they will get old. But premature puncturing solely depends on the install. Half the time you get a real smart one who mounts the sway bar against the bag and guess what - you're gonna pop the bag.
My experience: I never had a single problem from day one. When I installed my system, it all worked perfect the first time and I never had any trouble with it. You just gotta make sure everything is hooked up right and make sure nothing is near the airbags.
When I bagged mine, I honestly thought that I would get more lift, but I was kinda disappointed in that.. The maximum height was lower than the 3" drop that I had before I bagged it. Of course, I set it up so that I could lay the frame, so 6 or 7 inches was about all the lift I got. This happens to be the reason I got tired of it and decided to sell it. It actually rode great considering it was 3" off the ground. The real problems were the big dips in the road that made the frame scrape now and then.
I was always happy with the way it looked and the looks I would get with the bagged truck. But I kinda regretted it when I went to sell it - it made it a hard sell and I didn't get as much for it at the dealer when I traded it in. If you bag your truck, I suggest getting a beater to drive if you live more than 10 or 15 miles from work or school. I drove mine every day, but the drive was very mild.
I can't tell you yes or no about bagging your truck... it's definitely a personal preference thing. The pro's and con's are pretty much equal, so I guess it's all up to you.