leolav, The Tank uses Hydraulic wheel motors and hydraulic pumps that move the machine which is way heavier duty than hydrostatic transmissions on Cub's Z-Force. The trans on the Z-Force is made by Hydro-Gear, the same ones on Toro Timecutter, Husqvarna's Consumer Z and Hustler's. It is a good and proven unit for mowing up to aprox 2 hours per mowing (weekly, as most homeowners). The Hydraulic style unit are designed for 8 hours per day or more if you really like to mow. They are very different however, the Z-Force has been great and is built better than some of the others in my opinion. Another one to look at is the new Snapper Z that has the Hydraulic drive at at price that's $1700.00 less than anything I've seen, at only $3899.00. I'll be glad to answer any questions you have.
Stewart, I am a Exmark dealer (however non stocking) and they build some of the best commercial Z's on the market. With that said Toro owns them and sells their Z's at a better price. Both the Toro and Exmark are built in the same factory and they use the same paint. The major differences are the decks ( Exmark uses theirs and Toro uses their design) in which Exmark had a 10 gauge deck that was heavier than the Toro until 2004 Toro models rolled out with a 7 Gauge deck that reinforced to the hilt. I think it's the toughest deck I've ever seen on a Commercial mower. Toro with their company Exmark own 42 % of the commercial market. The next player is less than half that. As relating to the Tank, the tank uses the same drive components as the Toro etc. , however if it was a commercial application, I'd recommend the Toro, If a homeowner I will let the customer drive both and make his decision based on his comfort level. I think for residental use any good commercial mower will hold up. Back to the Exmark, they come through a distributor ( who has to make money) while the Toro comes to a bonded warehouse in NC holding prices down. Toro parts and Exmark parts use the same part numbers but Toro parts cost me less which in turn costs the consumer less.