Well, after reading all the posts by Wirken and the detailed accounts by Envy I just had to try a tank. The unit had 50 hours on it and was a 29dfi 60". I took it to an open lot where I mow every two weeks. The lawn is farily thick in parts and weedy in parts. It is a good mix of Northern grasses. I sharpened blades before taking it out as dealers never seem to provide a machine with sharp blades. The blades are the offset blades that apparently come from the factory. Anyway it cut pretty well but always seemed to spit out small golf ball size wads of grass. This was on the thin section which had alot of dew. Envy said his clumping and double cutting problems were eliminated with this beast....on to the thick stuff. It cut pretty clean with a few stringers in thicker grass, but the clumps grew larger. Huge wads would build up on the turbo baffle and unload a baseball mit sized wad of pulverized grass. Real purtty! The wads, large or small are very hard to disperse...no, impossible, especially the large chunks. I was blowing wads everywhere! On to a lot that I mow once a month. The XR-7 with no baffles would cut cut this lot pretty well and handle it with speed of maybe 3 to 4 mph. The Deere with 7 iron II would move at greater speed then the Hustler and just flat out slayed it. Cut in unbelieveabley well. The Tank was a chokeing pukeing pig. I killed it creaping. I think the turbo baffle kept the grass from clearing and really bogged it down. Cut was terrible. Grass was pretty dry by this point. Next property was 3.5 acres of lakefront with a good mix of grass. Grass was dry! Still spit small wads in medium to light growth and tossed some wads in the thicker stuff. Cut qualtiy was good but mess to deal with. Next I took it to a few decent bluegrass lawns with some fescue in the rears and it cut pretty well. Grass was dry and growth was light. Striped nice. Next I cut two lawns with good thick stands of bluegrass. It still tossed small wads at best, and large chunks on occasion as it built up on the turbo baffle. Chunks were impossible to disperse. This is very frustrateing. I let my worker use the machine to compare it to the XR-7 and after 5 minutes of mowing he was ready to be done. Although I think it cut slightly better then the baffled and air lift kit mounted XR-7, the difference was not great. We both prefered every aspect of the Super Z to the Tank. Just our preferences. I did not hint of my opinion, his opinion was unbiassed. As far as the DFI 29hp: It started nice and purred right along. RPM's no without blades engaged and moving at good speed was at 4000. It was not lacking rpm's. I was able to really drag down the mower and kill it in tall thick grass. I could have likely killed it on two weeks growth at slow speeds. It is a gas sucking hog! I drained 6 gallons of fuel in just shy of 3 hours. I ran her hard, but that is insane. I would never own this engine for that reason alone. A side note, at a Ferris dealer they had a 3100 series...I believe with the 32 hp Briggs. The sales guy started a dead on cold floor model. He imediately dropped it to idle and engaged the blades. They turned on and spun without a flinch. This is on a 72! I have to choke my 30 Kohler til it is very warm just to get the blades engaged at full throttle or it will die. That 32 Briggs must have a great torque curve! Anyway that is my experience with the Tank. Mowers and their performance is so regional in nature. Demo, Demo, Demo!