Hey guys. Don't take this as tent-bashing, I've just been trying to cover all the pro's and cons.
I picked up a used fibreglass cap for mine ($100, and was even the right colour...woot) for sleeping in.
I just wanted something big enough for me, and something that didn't involve a lot of screwing around to set up or tear down. (Go in, close tailgate then close the capper door...that's about as simple as you can get) I have a fold-in-half cloth covered foam mattress from a tent trailer...it's 6" thick and 24" wide and exactly 6' long. Perfect for me to lie down on and still have room for 3 HUGE stacking storage bins beside me, plus a full size cooler.
Plus I was sick of setting up tents, and having to put them away wet and dry them at home, etc etc...
Here's the cons I see with a bed tent......
1 - you still have to set up a tent.
2 - you still have to put away a wet tent and dry it later, etc.
3 - you have to empty your bed out to set it up. (don't you?)
The price is right on them, and they certainly look cool

, and I haven't ruled out selling my capper and doing the tent thing but I just want to cover my bases...
One question I have is, if you're going to empty all the stuff out of the bed, set up a tent, stow all your big stuff under the truck for the night, wake up, pack up a tent and load all your stuff in the bed again....why not just leave the stuff in the truck and set up a regular old tent?
Again, no, I'm not tent-hatin'... I'm just asking...
I suppose, living in eastern Canada I don't have to deal with snakes and scorpions and stuff....is that the big attraction with being off the ground and in the bed of the truck?
Really...I'm just askin'!