What is unusual or special about it.

Nothing really unusual, just very heavy built...deck is very thick steel, and only has one adjustment lever for deck height...I went ahead and bought it, so far I'm very pleased with it. That 8.75 Briggs is a strong engine!

I've never seen one in person, but did check out their site. The offer two 21" models. A self-propelled with caster wheels. I don't like caster wheels so I'm not interested. And a push mower with fixed wheels. I don't like to push so I'm not interested. Both use a 190cc. Briggs. I'd probably stick with Toro for about the same amount of money.

All I know is that they Sponsor Numerous Nascar Teams lol . As far as Mowers , yes they are quite Heavy , thought they also Manufactured Commercial Grade rather than Homeowner Designed Units ?

This one from all appearances is commercial grade as far as the deck construction. I don't know how well the engine will hold up over time, but so far so good...I ran it about 2 hours today and it performed flawlessly, and doesn't seem to use that much gas. I do know it has the fastest self-propel I have ever used...4.2 mph is what the manual says, I know I had to break quite a sweat to keep up with it when I ran it full speed, glad it is variable! It mulches pretty nicely, and sure isn't hurting for power, seems to have quite a bit more than my old Duraforce Lawnboy did. All in all, I'm very pleased with it.