Ben, if I could have the same relationship with Petra Hilleberg that I have with Henry, I would gladly swap. ( nothing to do with tent design, BTW)
That is my main problem with the BD Lighthouse as a winter tent, no vestibule, and if Glen thinks the Rainbow is fiddly, try to fit the BD vestibule to the Lighthouse…
I did send to BD a design of a 6oz or so vestibule for the Lighthouse (in silnylon) they came back with the standard "we'll pass it on to the design team" bit and never heard from them. I noted that the Skylight has one…
The Unna was originally designed with a larger interior ( possibly big enough even for you) in place of a vestibule, and that is fair enough for the long Scandinavian winter.The problem is that enough people want to buy it as a year around tent and do not want to take boots and wet gear inside it.
I would expect an unsupported vestibule, maybe another 8 to 10oz ?
Of course they could come out with a lighter fabric (for the inner) and keep the same total weight including the vestibule…..
If you don't really want a freestanding, the already have the Nallo for around that weight.
Franco
John, if you are still here…., what is your size ? I think that you mentioned that already but I am too lazy to look it up
( to understand the subject it helps to be Italian )

