My wife and I discussed this when she first saw these tents. There are several pro's and cons, and I'd be interested in hearing from owners of roof top tents on some functionality.
Pros that I can see:
don't have to worry about pitching on the ground, can avoid rocks, roots etc.
don't have to spend time "pitching" the tent, most have quick setup. However, like @airwolf39
says he wants to take it on and off every weekend, so this "mounting time" may cancel out the lack of pitching time.
You can have an extra layer of separation from critters. Of course bears and cougars can still get up there easily. I think that you may have an easier time avoiding other things like snakes or skunks.
You have that "wow" factor, when you roll into the campground, your tent is on your roof....man!
Here are some Cons/questions that I have:
When we go camping usually we set the tent up camp at a site, then we will go and do things, sight see etc. With this roof top tent this means you have to take it down and put it back up every time you want to go out. Sometimes we just need to go to the corner shop for some eggs or milk really quick. Or take the trash down to the dumpsters at the campground. Having a tent strapped to the roof of your car makes this type of thing tricky. Similar to RVs.
When I pitch a tent, we usually spend some time finding a good spot. This spot needs to have a lot of space void of roots and rocks, not a problem with a roof top tent. Also though, you want this spot to be relatively flat
. A lot of times this can be done with some finesse. What happens if you can't find a flat spot to park the jeep? That means you're tent will be on a tilt. When you sleep on a tilt on the ground, worst thing is you wind up in a ball in your sleeping bag at one side of the tent. This happens to one of my daughters no matter how slight the tilt may be. What happens when your jeep is on a tilt and you move to the edge of this tent, that is 5 feet off the ground?
About "pitching" these types of tents. Is this something that you take it off the roof, set it up, and put it on top of the roof again and secure it? Or do these things stay attached to the roof while you set them up? Not that it's "that big of a deal" but this thing weighs about 150 lbs, so it's not exactly as light as your normal 4-8 lb tent. Having to hoist that thing up and down will definitely take a few people. If you leave it attached and set it up on the roof, how easy is this to do? Do you need the ladder to do it? Or do you climb up on top of the tires or something?
Is the roof actually able to support that? This question was raised by others. I get it, the book says that it's fine. But if you bust your roof b/c you put one of these tents on there, is that damage covered under warranty? Or would you have to pay to fix it yourself? How many people have owned one of these on top of a compass? I always see pictures of them on beefed up off-road wranglers with huge rollcage bars and such. Are these going to work on stock cross bars etc?
This tent is on your jeep, on the shocks/springs right? So when one person moves the entire thing moves? So when one person has to get up does this shake the whole jeep? This would bother me or any other light sleepers.
Being not-so-nimble anymore, I don't like the thought of my wife or I having to climb down a ladder in the middle of the night to go to the bathroom. I guess some young folk this is a non-issue. Maybe after having owned it this would become second nature, but to me just getting up out of a sleeping bag, opening a zipper and getting outside is enough complication.
Speaking of ladder, where do you leave your shoes? We have a vestibule in our previous tent and we leave the shoes outside. Bringing muddy/dirty shoes into our tent is a no-no. Do you leave your shoes at the bottom of the ladder? or is there somewhere at the top of the ladder?
It's very tall. Height is something to think about. Besides low-hanging branches that may be in your campsite, many times when camping there is very adverse weather and I will setup an additional tarp above the tent, as "waterproof" rainflys are not actually "waterproof". Every material has its breaking point, and a good old fashioned supplementary blue tarp has kept us dry for many years. Setting this type of thing up over a normal size 6-7 foot tall tent is one thing, but with this 4 foot tent on top of the jeep that will add some difficultly.
Finally, $900 is about 3x the cost of a GOOD - meaning really nice - 4 person tent. I've been shopping for a new 4 person tent and the good ones are 250-300$. is having it on the roof really worth 3x the price?
To me the roof top tent seems like a gimmick. If you're young and agile, have plenty of disposable income, and just want to tour around with a significant other and spend only 1 night in any spot while you vagabond around seeing the sights I guess it could be fun. I don't see something like this suiting my camping needs, and I'll stay on the ground with the snakes and skunks. I have too many questions about the roof top tent, and not enough assurance that it's going to make camping any easier.
Plus when I do want to get "above" things, I just set up my hammock and it's very easy to tie one of those between the roof-rack and a tree.