I've just been using the Virtual Concierge link in my reminder emails. I have a particualr room at the Renaissance TImes Square I like, and the old way they never caught my request, but with Virtual Concierge they have been honoring that.

I tend to think that using this for requests might actually be a better option, since you can more clearly type your needs (not limited to 45 characters!) and since it's being handled most lilely at the property level, it's getting local attention so if you request a particular room number, the property can actuall "room block" that room for you and the computers will automatically assign guests to that room prior to your arirval date that are due to check out that day so they don't inadvertently book a stayover in the room (having worked the desk for a few years in college...)