cork vs foam

I'm partial to cork, we have foam on the club layout and it's not as stable when pressure is applied. (track cleaning, work sessions, etc.)
I also prefer cork........For starters, I nail down my track, and nailing on the foam is horrible. I tried some foam, and I had much more trouble bending it on the curves (it wanted to crinckle along the inside edge). It can also be an issue after you ballast......I used some on an NTRAK module, and due to the amount of handling, any time the ballast got any pressure, the foam would give and the ballast would crack and flake off. The foam IS much quieter though.
I prefer Woodland scenics 12"x24" roadbed "super sheets" on my switching layouts since it puts all track on the same level like you would find in a industrial park.
I just laid down 2 rolls of WS foam for the dual mainline running thru my yard and I would never go to cork. The foam is so easy to bend on curves (mine are 24.5" radius at the tightest) and you dont have to worry about it cracking. I glued mine down over styrofoam using Elmers white glue and in about 3-4 hrs its all set up. I found it especially easy to push track spikes thru with my thumb to hold it on the curves...and then a couple blocks of wood over top to hold it while glue dries. It is alot softer than cork, but I am gonna say that a personal layout wont have the heavy use of a club layout and so I think the foam is the best way to go, and its alot cheaper too...
Good Luck...
I love Cork, never used foam so really have nothing to say about it. Never found cork to crack when bending around any of the curves on my layout. I like that there must be some type of chemical reaction with the track nails as over time they sort of bond with the cork. There not difficult to pull out, but the hold tightly. My guess is there is a certain amount of moisture that get's into the cork and corrodes the nails a bit.

Never bought the fancy turn-out cork parts as cutting the cork to the shape of a turn-out is stupid easy!
I've had lots of experience with cork, and minimal with woodland scenics foam, and I wish I had absolutely no experience with the foam. On our coffee table layout project, my father and I used WS foam for most of the roadbed, and we've had no end of trouble with it not holding the glue and causing track misalignments because of how soft and springy it is.
The biggest concern I have with cork is that when your "unzip" the two halves there is always some flash on one of the halves which keeps you from having a nice clean bevel.
I've used cork for HO and WS foam for N. I'll echo all of the above comments about both - each has advantages and disadvantages.

I do like the fact that I can hand sand cork down to a lower profile and I use the dust for ground cover. Can't do that with WS roadbed.

I'm going to experiment with thin cork sheet when I eventually expand my HO layout.
I prefer WS Foam. Easy to put down with Elmers. Secure the track with chaulk that dries clear. Never noticed any springy-ness, esp after ballast is down.
I like cork. It seems to me that any material where you can push a track nail through with your fingers will come out when you least want it to. Besides, I'm an old guy and unwilling to change just on principal. Where's that Athearn Little Hustler with the rubber bands...