A couple of years ago I bought a Coleman 1-man for the wife and to be honest I'm not very impressed with it. The design and construction aren't what I'd have expected for the price. You can see the stitching being stretched horribly when you put the poles in, and the fabric always seems to wrinkle and flap no matter what you do with the pegs and guys.
You can easily get a two man tent well under two kilos. Even when camping solo (which is what i do most) I'd go for that every time over a one man.
I have quite a few tents and bivvies, and some of them weren't cheap. A lot of the time when I travel I'll just use a bivi because I don't want to spend time setting up and taking down a tent, but if I don't have time constraints I do like to set up a tent. I have a couple of very cheap single skin festival-style two man tents, and if I'm using a tent they probably see more action than anything else. Quite often I'll put a tarp up too, that's what I call real luxury.
Condensation is always an issue but the two festival types that I have do have good ventilation. They have a big mesh vent at the top with a detachable cover to stop it raining in. The door flaps only zip up the middle, not at the bottom, so if it's raining and I haven't set up a tarp I can peg the bottom out for a good vent. If I've set up a tarp I'll just tie them out of the way. They have fully-zipped insect screens which you don't always get on bivvies.
I carry a face flannel to mop up condensation from the inside of the tent, tarp or fly. I use a bivvy over my sleeping bag even when I'm in a tent to keep condensation off the sleeping bag.
