I am going to tell it the way it is, and I have owned Hustler Super Z's for several years. I have the Bad Boy AOS diesel sitting at my house, and I have been running it for about 30 minutes in the roughest areas I mow. I am talking about small washed out areas where water runs down the slope that makes you feel like you are hitting waves in the ocean. This is an area I pull the speed down on a Super Z with flex forks and flex seat. Most all zero turn mowers would beat you teeth out of your head in this area. I went through the area at full stick just to see if I could stay in the seat and I did not come close to bouncing up, I absolutely could not believe it and no one else would unless they did it themselves. There will be more people than myself running it tommorrow and I will come back with their comparison. I knew the Bad Boy AOS diesel was a good bit heavier than the Lightning model I ran in the same area. I was totally shocked that the BB AOS rode better than the Hustler Super Z because the Lightning model did not. The BB AOS is a hoss of a mower, the extra weight on the AOS actually makes the 4 wheel torsion rubber suspension work better. The Lightning model has the same suspension but does not force the torsion rubber to work because it is not heavy enough to compress the rubber. This make the bumps jar the operator more, where the AOS being so much heavier makes the rubber compress and work the way it was design. The Lightning model actually needs a lighter rubber composition because it is not heavy enough to activate the same suspension setup as the AOS due to weight. I put the AOS and the Super Z side by side for a speed comparison, both say they will mow at 15 mph. I was running the AOS beside my Super Z in a waterway about 700' long with a slight uphill slope (very slight). We ran the mowers up the slope and the AOS was a little over 1 mower length in front, we turned around and started off side by side and at the end going down slope the Hustler was 1/2 mower length in front. We can all say the speed is exactly the same. The 28 hp Cat is affected by speed and heavier growth, the rpm's would drop noticeably, the same as my 28 efi Kohler would. The 32 Vanguard I ran on the Lightning model did not change sounds in anything but 30"+ tall signal grass. This is a 72" deck on the AOS while the Lightning was 60". I will tell you the 35 Vanguard will blow your mind with the amount of power it has. When my dealer was at the factory last week the BB people were telling him the big block Vanguard was unstoppable and the only difference in the way the 35 Cat handled the AOS differently was it used less fuel. I will say the Super Z is still the best handling mower I have ever operated, but the AOS does ride a little better with the additional weight.