If this helps, I had a Calfee Luna pro which I bought when I was 232 lbs. I would climb hills with it up to 16% and didn't notice any flex at all in the frame. The bike was also extremely comfortable. My bike shop recommended the Calfee for cyclist doing century rides.

I have since replaced the Luna Pro with a Calfee Tetra Pro, the next model up and my weight is now about 210 and still no flex on hill climbs. The reason I changed out the frame was because the Tetra Pro had a taller head tube which gave me a more comfortable riding position.

If you are considering a Ti bike. I would consider Kish Bikes. They make custom Ti bikes for less money than Moots, Seven or Lightspeedd stock frames. I think they make great frames for the money. Jim Kish teaches frame building at the United Bicycle Institute. He can also build a custom steel frame for $1500.

http://www.kishbike.com/about.htm

If you really want to buy a frame on the cheap, look at Habanero bikes. They can build you a stock Ti frame for $895 or a custom Ti frame for $1295.00. The bikes are made in China by an aerospace company. However, the reviews have been very good.

http://www.habcycles.com/