Have used both and by no means is the pro-core twice as fast so by running the verti cut unit behind it in stead of an extra man on a separate machine you will save some monies. Be careful though and make sure you start high with the verti cut unit. Sales man was running late, said the unit was set properly and when we dropped it down on the practice green, well lets just say a chisel plow would have been less aggressive
If money was not an option, both units have a place and work well. You'll be amazed as to how much material you can pull.