I have also used the online "request a reservation" form...I've used it twice...as the previous poster noted, both times I got an near-instant "we'll get back to you" message. On my first attempt, I messed up my dates and asked for a reservation at a resort that's not my home resort at 9 months out...about 3 days later a CM wrote me a very nice email telling me I couldn't do a non-home-resort ressie til 7 months out.
So, I went back to the form and resubmitted my request asking for my home resort, and got a response (about the ressie) back 5 days later confirming that I had a reservation just as I'd requested it. I zapped back a "thank you" email and the same CM responded that she'd been glad to help and wished me a magical day...
So, I deduce that once you get an email from a CM, that's the CM you keep dealing with if you have back-and-forth to do...
I love the online system...probably isn't good if you're trying to book for a time when "time is of the essence"...but works great for non-peak times between 11 and 7 months...