I am currently at 1750pts and am thinking of going to 2k. I am considering for numerous reasons buying a unit of 5 Grey Knight Terminators to employ as a counterassault unit. Furthermore, I am sick to death of painting Cadian Guardsmen and am looking forward to a more complex painting and modelling project. The unit would clock in at several hundred points (I understand that there are some draconian rules about point costs so I will be vague) and I am wondering if they're even worth the trouble? Have you lot had any good or especially bad experiences using them? I am thinking 1 Brother-Captain, and 4 Terminators, maybe with a psycannon.