I think it depends a lot on what you put him to, and what you are looking to breed. I've seen some lovely ones, but also a lot that are very plain. I have a rising 3 y.o. by him (which isn't coloured!) out of a 3/4 TB ISH mare which I plan to event when he's older, and which I'm hoping will turn out very nice - although it's quite hard to tell at the moment as he's going through a slightly llama-like phase and a bit of a growth spurt so his back end is currently several inches higher than the front end!
His son Cavalier Jump for Joy is quite nice and piebald and he gets an awful lot of mares but of a very mixed bag so one or two nice ones but the rest pretty. As for Two for Joy, there is a trickle of nice stuff, again if the mare is good he can throw quite nice stuff.