I've got one and they are excellent - if hideously expensive.
It's a very versatile hammock as you can have it open, with bug netting or completely enclosed - like a suspended tent.
The external pockets are extremely handy for gear - although I would question their insulating properties in really cold conditions. I've heard of people using blown up zip locks in them with some success, although I've yet to try that myself.
The best thing about it IMO is that it has enough attachment points to make it easy to pitch on the ground - like a basha - for when there are no suitable trees or when it's too cold.
Go for the extra large tarp which is an optional extra - it's worth it.
Cons? Well apart from the price, it certainly won't be spark proof (unless it could be treated?) and whilst it is very comfortable - you won't be lying as flat as you could in say a Hennessy. It is possible to widen it, using the same attachment points as the ground set up - but you end up with rigging lines all over the place - so it isn't really worth it.
To sum up - expensive? certainly but you're paying for the Rolls Royce of single person outdoor shelters.
