I'm also not entirely sure that a woman's posting necessarily gets quicker responses. It may be visibly verifiable that they get more in-thread replies (although I'm not inclined to do the data input on that), but it's impossible to figure in replies that come through PMs, the chat room, or instant messengers. Personally, I'm more likely to PM someone in regards to an RP, rather than post in their thread - partly because I don't want to make the idea look taken if we can't work something out. (Honestly, if you see an idea thread with 20 responses and one with none, which one is going to look more 'available'?) Also, there are some people that lock their request threads for personal 'tidiness' reasons. There's no way of telling how quickly those ideas are taken unless a) you stalk that thread and b) they update the thread immediately on a plot being taken. Again, more effort than I'd be willing to take to analyze that potential trend.
Also - suppose that you agree to this 'trade-off', and within the first page of responses, you find that the other person's style (not plot) is impossible for you to work with? Then both of you are stuck with two RPs that one or both of you aren't enjoying.