Voyager Superlite maybe (lastest version 1.5 kg apparently) though still pricey admittedly? Had I not got the Nallo in a sale for £240, I suspect my attention would probably have turned to this.
Someone may prove me wrong (gladly) but I think you might struggle to get a quality 2 person sub-2Kg tent for much less money - I'm sure John or PH would able to advise you.
Hopefully others can recommend, otherwise good luck in what ever you decide, even if it is only to accept Crux's very generous offer, entirely understandable! Maybe do one tour with the Crux, and if weight turns out to be an issue in the mountains, then your longer-term decision might be made for you!?