I used to use the cshyde C4 NGen thin pad (similar to the Sphex) and the surface was nice and slick but it wasn't padded. They make padded versions however and in large sizes as well. Check them out.
looks pretty tempting for a hardpad lover, btw how the fuck is someone supposed to play with the mouse cord on the right side of his hand ? And what's the point of using a large mousepad with a mouse that obviously is incapable of tracking at high speeds, anyone daring enough to try that combo ?
edit: before someone calls me biased, I tried master pad lowsense some time ago and it was absolutely horrible !!!
Func F30.R/F10.S 17" version http://func.net/products/fseries/index.html
Razer infrared mice will not work on it though, thanks to their infrared sensor being very picky about the surface.
I actually just found a piece of plastic that was part of the packaging of something that I cut out into a mousepad shape and taped to my table. Works perfectly.
Thanks for all the suggestions though.