Saw a short intereview with Leon Cooperman on Forbes this weekend. He touted Atlas Energy and SD. From what he was saying he felt there is 40-50% value based on the underlying assets of ARP and APL. But it also seemed he was doing the old "get paid while you wait" for this value to be found.
On SD I believe he said they thought its worth about $10.
The interview was on Forbes website - can't put links into yahoo any more so not sure if you can still access it or not.