I can speak for Willow St, Exit 7 on the Cape. The trails are definitely rideable -- they drain remarkably well, and even where they're soggy, they have a carpet of leaves that prevents mud (and ruts) in most places (unlike TOT, which has many areas that are susceptible to mud). There are lots of sticks and trees on the Willow St trails, but I'll take care of them over time, so just go around them for now (for anyone that decides to ride).
Sea Sports has an updated map and parking info here (scroll down for Willow St): http://capecodseasports.com/bicyclin...untain-biking/