PhD...easy to use. Tracks pretty well with my set up. Honestly better with my Stellarvue than with my Orion ST, but still does a good job either way. To date...longest I have done is 15 mins exp with an f12 with no issue.
PhD is easy eanough, but CCDsoft or MaximDL programs are more robust, they don't skip out nearly as much. Right now I use Maxim with the Starshoot and in another window open up CCDsoft for the SBIG. It's kinda stupid to do that but MaximDL for SBIG camera's costs a lot of money.
Like Trevor said phd works great. I use it w/a SSAG and Orion st80 and a GOOD set of adjustable rings. Made the mistake of using hinged rings at first, a great place for flexure. Charles, I saw you made mention of maybe going to a longer focal length guide scope over in groups, the only thing is to be careful that when you get out of the main milky way belt good guide stars get a little harder to come by. Marc PS if phd can guide that Keck setup that Trevor has it'll guide anything.
I use PHD from Stark labs. PHD...Push Here Dummy!! Enough said. I've had good luck with it. I'm using an 80mm Short tube guide scope from Orion as the guide scope and am able to get pretty good guiding with the CG-5 pushing a 23# set up.
Ive used phd, have it installed. Find that the other programs work better but that could have just been poor polar alignment on my part. Ill bust out phd guiding next time i shoot. Btw, i emailed orion and asked them to make drivers for ccdsoft and anengineer replied and said theyd look into it.