Second Skin Sludge is on sale for $39/gallon right now. Thats about $10 off the normal price. I'm going to order 2 gallons this week and see how it works. So far past users love the stuff but hate working with it.
From what I've read:
1) never spray, just paint it on
2) SS Sludge is more like a paste
3) Dynamat original falls off regardless of what temperture its in
I personally use Raamat in my truck (see sig), but Dynamat extreme, FatMat and Secondskin mats have worked well for me also. eD V1 SE sucks, and is rumored to be rebadged Peel and Seal.