What Steve is saying is right, but given all the circumstances, i'd take the D&D for a few reasons -
Youve paid the guy, taking him to court will cost you money and if he hasnt got any money you cant get it back, been there, done that, lost alot of cash to a builder and then lost more trying to persue the money after geting a CCJ against him, turns out I threw good money after bad.
If this was a cash job, he could scarper, if you decide to tell the tax man, the tax man could become interested in where you got the cash from to pay him, that may or may not be a plesent experience for you.
You make this guy float and set it again and he cant do it you are back to square one, just a long time down the road.
Time is ticking now, skim on d&d board will be dry enough to paint in 7 to 10 days so technically you could be painting, ready for 2nd fix within two weeks of him finishing, or if he can board and skim one room at a time, you can work behind him. Float and set however could take 28 days of so until you can paint.