Are you sure it's the saddle? I had some numbness problems, but they were mainly due to poor bike fit... stretching too far to reach the handlebars, which were positioned too low, and I had the seat up too high (also caused me ankle troubles). The end result was to put too much of my weight in the saddle, and also had me tipped forwards, not letting my ishia take enough of the weight. Seat angle and forward/aft can also play a role. Bike shorts help.

My bike fit was not obviously wrong... the numbness would only set in after an hour or so, and the ankle pain took most of the season to become obvious. I suggest making some subtle changes to your fit and see if that helps over the course of several rides, before you try a new saddle. Your body can tell you a lot about fine-tuning your bike fit.

One last thought; your body will adjust to some degree as well, as you spend time in the saddle. I used to get terribly numb on the balls of my feet and my palms (again, only after an hour or more)... then it went away on its own. After taking a few weeks off from long rides (but still doing short rides every day), I went for a couple long rides this week, and the numbness in my feet was back! I'm not thrilled, but at least I know that I will re-adapt soon.