Just bought this. Brand new... assembled out of the crate in front of me. First ever new piece of equipment.
I had a small budget and was initially going to go with the low end 54 inch, but the more I looked at it, the more I figured it wouldn't hold up.
Looked at the next level up (Z-Force) and while it is certainly not commercial duty (and not the commercial price) it did share some parts in the drive and engine that let me think it may have at least some longevity and stamina. The Hydro gear ZT2800 drives has both the reservoir and filters (low end units do not) and the mid level Kohler engine. It also has a fairly stout deck with greased spindles.
Only mowed a couple hours so far. So will see. I rate only 4s as only commercial would likely get 5s from me. It was the best I could do and stay out of the 7 to 10k range and have a reasonable cut width.