I finally went with a set of Williams System 30s for my Madone. I've got over a 1000 miles on them so far this year and they have been bulletproof on the less than perfect roads I ride on. I cannot detect any flex on them and don't get any rub in hard cornering like I did on my original Bontragers. They do spin up much easier and make a big difference when climbing.
I weighed them when I got them and on my scale that came in at around 1640 grams with the rim tape installed. I had the wheels in something like 2 or 3 days after ordering. Do a search on my name and you'll find the informal review I did on the wheels.
I should mention that I weighed around 180 when I got them and with it being still quite cold have ridden them with close to 10 lbs of winter gear on. They have done well with that sort of weight. I rode them with Conti GP 4000s in 700 x 23 until yesterday. Yesterday I put on a new set of Conti GP 4000s in 700 x 25 so I can ride a little less pressure to help smooth out my rides on rough chipsealed roads.
I actually am looking for an even lighter (but strong) set of wheels myself right now. These will go on my LeMond Zurich. I am considering other brands only because I want to use different sources for my wheels in case that ever is a durability problem that comes up over the years.