First up, I have no direct experience of roof tents. I have been looking at them over the last six months for camping with the Doka - although I know people have set up Doka cabs for sleeping in, I'd rather cook/eat/live in the cab and sleep in a tent rather than sleep inside and cook in the rain
Like the OP, most of my research seems to end in "£$%^ me! They're expensive!" and "Do I really want to be carrying around that great big lump on top of the van?"
I've now pretty much settled on buying one of these -
http://www.cot-tent.co.uk/" onclick="window.open(this.href);return false; - in the double version, probably within the next couple of months. My reasons for wanting a roof tent were basically:
- quicker to set up than pitching a normal tent.
- works if you're on hard-standing.
As far as I can see a cot tent will do that just as well, but would pack inside the vehicle rather than being an airbrake on top, and gives a bit more flexibility if you fancied sleeping at ground level.
I've seen a few of these up close, as I race motorcycles against the guys who import and sell them (via the website I linked) - we end up sleeping in a lot of gravel/hardstanding paddocks at events. They seem to be pretty well made, and certainly a step up from my 'short-term-fix' of a Decathlon pop-up tent on the pickup bed
Actually, I reckon if you really wanted to (or needed to be able to sleep within the footprint of the vehicle) you could probably turn one into a roof tent. The picture below is from an Aussie guy building (believe it or not) a fold-out camper sidecar outfit, and using an adapted cot tent for the sleeping part (as far as I can tell, the rest of the sidecar body is mostly for keeping beer in

)
By comparison, bolting one to a roofrack would be pretty easy

. I might even try it in the long term.
