I picked up a pair of Soul C5.0's (50mm depth) in late February and my experience lines up with datlas'. My older wheelset was a set of Mavic Aksiums. I weigh 143lbs.

I do find that it's easier to maintain higher speeds but I don't really notice much of a difference under 20mph. Around 25mph is where you start noticing it more, but it's still not earth-shattering. I find it is easier to keep the same speed in a paceline than with my Aksiums, sometimes I have to get out of the draft a little more than with my Aksiums when I find I'm getting a little too close to the rider in front of me.

Re: crosswinds. I'm relatively light weight-wise, and I did notice a difference between my Aksiums and the Soul 5.0's in windy conditions. It's not like I was getting blown all over the road, though. Crosswinds were only a (small) problem on fast downhills. You just have to get better at bike handling. Took me a few weeks to get used to it, but now I'm fine. I do find that when I'm getting close to 50mph I start becoming a little twitchy, but I think that has more to do with my poor descending skills than with the depth of the wheels.

I do love the wheels. High quality hubs, lighter than my Aksiums (my particular C5.0's came in at 1410grams on my home scale), and 50mm depth that is noticable to me at speeds >22ish mph. They're a little over your budget, but in general, a deeper rim won't necessarily blow a lighter rider all over the road.