Hey!  I think it really depends on the running speed of your layout.  I didn't bother with anything, as my layout is an 8 x 4 terminus to fiddle yard, which means my trains won't really be running very fast.  However, I would definitely recommend putting something down if you're going to be running the trains at a reasonable speed, as no matter how quiet the locos are, the rolling stock tends to make quite a lot of noise if going fast!  Any chance of getting some info on the layout on the layout page?