I've got a wanga. Riding it was really great. had it set up with a surly instigator fork and surly/rhynolite wheels. Came out to about 24lbs. You could probably set one up at closer to 20 with lighweight stuff.
I mainly rode it fixed offroad and it was a blast. the bike is solid and the welds are descent quality. I'm a huge fan of the sliding dropouts.
the problem was that it was a little small. Ordered it out of a catalog as my first mountain bike. Now trying to get rid of it unfortunately.