I just returned from playing BB Old and Cashen. While I would highly commend a second round on Old versus Cashen, our Cashen round was free...so my buddy and I played it with our wives. IMO, it is unplayable for 99% of women and most men. The forced uphill approach shots are near impossible, yet A players simply fly over these areas. If you cant reach many greens in regulation, you are screwed, unless you can nip wedges off firm turf, hit them straight up in the air and make the ball stop on hard greens...And if you can do all of this, you can probably reach the green in regulation...(I cant tell you how sad it was to watch the ladies ping pong it over the greens and back... and they HATED the course.)
My wife lost a ball and I was standing 15 yards away from where it landed! It is also target golf. If you are a good player and dont try any heroic shots, play all the par 5's as three-shotters, the course is playable. It is also a beautiful piece of land with stunning views. So if the round is free, take a buggy (there are many really long walks), a 12-pack, play a two-man scramble, and have a fun time.
Waterville is a must.
I guess playing Old Head is worth the drive just to see the views (once.)