One of the main differences between the Lightwaves and HBs IMHO is the pitching. Hilleberg pitch all-in-one, Lightwaves pitch inner first, so HBs are up quicker and with less faff. You also have the option of unhooking the inner for more party/cooking/workshop space in bad weather. That's enougfh to convince me the HBs are better for my particular preferences though having looked hard at the LWs I'm pretty sure they'd do the job fine and I'd have full confidence in one. With a smoother top profile from the throw-over fly they'd probably be quieter in a real blow than the HBs which is a nice thing, but I'm more interested in easy pitching myself.
Another thing I like about HBs is the possibility of a twin-porch design, not avaialble in the LW range. I use a Kaitum 3, but the Kaitum 2 would fit your specifications pretty well I think. The Nallo or extended porch Nallo GT is a bit lighter, but not so roomy, only one porch and not so well ventilated. Nicer to carry, but not so nice to spend time in, so you have to decide where your priorities lie.
The Kaitum isn't the lightest thing out there, but it should be a fair bit tougher than the really light stuff and it's a palace in terms of usable space, important if there's two of you using it for an extended period. We actually got the 3 man version which is only a little heavier, and has acres of space. While HB list it at 3.1 Kg, mine is actually 3.0 Kg and you might want to consider it if you really want more space, but the 2 person version is already quite generous in that regard.
Very happy with mine. With a priority given to a nice place to live that happens to be usably light I've not seen anything I'd swap it for (and I looked hard at the LW t2 and the Nallo GT as options).
Pete.
Edited: 10/05/2010 at 20:34