I've tried the cork, foam and homosote and will say that I am divided between all of them. Each has it's own pros and cons, but non retain every pro we wish they had. Cork and Homosote are great nail holders. Homosote is a great noise dampener, but you have to get busy with the jigsaw and it's real messy. Cork is a good sound dampener, but not as good as the foam roadbed.
I'm still up in the air when it comes to the foam. I just can't seem to like it because it's just too smooshy. Not that it's not good, but after driving spikes into homosote, the foam just doesn't seem rigid for my liking. The prefered method is to glue the track to the foam, which works fine, but I haven't yet worked on any track that couldn't use a spike here or there to adjust it for whatever reason.
I have the Control Master 20 and really like it. It will handle pretty much about anything you can throw at it.:thumb: My new layout will be DCC, so I guess the 20 will become a power supply for the DCC or a Christmas layout.