Jakeman:
I looked at literature, specs and prices of Ventrac and Steiner before deciding on Power Trac. Unfortunately, I didn't get to try them out. My impression was that they are capable. They have belt driven front mounted implements rather than hydraulic. For similar packages of implements, I think Ventrac and Steiner were a bit more expensive than Power Trac.
If you can, drive all three and try switching implements, etc. I know Power Tracs sell themselves. I suspect that Ventracs and Steiners do as well. Part of the fun is in the research testing and deciding.