In reply to James Rushforth:
Since I've bought the Outdoor Designs Summit single-skin tent, I've been really happy with it. Highly similar to the Integral Designs Mk1 Bivy, used the old Gore Exchange fabric though.
When wild camping in the alps (in the valley), set up the under a waterfall by accident... minute condensation was the result, but then again I've had more condensation on a Nallo 3 GT.
Also used it numerous times in the winter (sub zero temps) and no issues.
I think Rab Latok 2 is the same product... and slightly lower (and thus nicer in the wind , would be the Latok Summit. Crux also has something similar I seem to recall. As does MHW (but it's spendy).
Were I shoppin' now, I'd get the Crux or MHW one, as both have this nice pole-sleeve on the outside unlike the Rab/OD version where you simple open the door and push the poles in. The MHW system, with partial sleeve and clips looks the best, but I think it also works out the most expensive one.
The I-Tent is much like the Rab/OD one, albeit highly popular one (as is the lighter version, Lighthouse or something).
So, my picks would be MHW, Crux and then Rab/ID/BD in mixed order...