Me four with the gray paw one! Well, I used to anyway, wish I still had it although my issue is more that Bond likes to flick the litter out of the (covered, quite high sided) tray bought because he does like to flick it around.
When I did have the mat I found it caught loads of litter, I used OKO too. The grooves and indents are of varying size too so it gets big and small grains trapped in it. I got mine from Zooplus (I really miss Zooplus now, for all the problems they have an awesome range, can't find any litter I like here, all seems to be the same just in different packaging!).