I've got a Silver Eagle 2700-60D, and overall, I very pleased with it. Admitedly, I'm not using it commercially, but I firmly believe it to be of entry level commercial quality: true hydro drive, not transaxle; heavy gauge construction; commercial quality, high hp engines; good cutting/striping and adequate discharging deck; respectable cutting mph...
Having said that, I have decided after 3 seasons with it, that if I were using commercially, I'd definately want larger fuel tanks (only holds 6 now), and maybe a suspension seat. At the time I bought it, the Classic was only an additional $700 (also came with an electric deck lift as a promotion), I think, but I was leaning toward a narrower framed machine for increased trimming capability. Yeah, I know, hindsight is 20/20.
Don't know why there's so much negativity toward the Generac engines, although their frequently seems to be just as much toward DC too. Mine's been the best engine I've had on a mower; lots of power with more torque than it knows what to do with. Just for giggles, I installed double blades on mine, and have noticed no discernable power loss, except in really tall (8" or taller) grass. I've had Kohler, Briggs, and Kawi on units in the past, and I can unequivocally say they’d be no match.