I'm really into Vita and 3DS. Those are my preferred trade systems at the moment. My next favorite is PS3. Any other "wants" on my list are probably just for collecting purposes.
My response time is usually really fast or really slow. If it's one I'm really interested in it will be instant, if not I'll spend the full 3 days thinking about it.
I realize my trade rate is awful low for having been a member since 2010. I mostly trade on Cheapassgamer and Goozex under the same name TylDurden as well as buy and sell a lot on ebay under the name Grahamily. You can check there for more ratings. I prefer to send at the same time so that we both receive our games ASAP but if I'm rated lower than you and you don't feel comfortable doing that I'm willing to send first.