I'm not fond of the extended length tube to incorporate the nozzle, looks rather cumbersome especially in tight areas.
I would also rather see a machine thats capable of those numbers on brute force alone. With what's available now, it appears the performance levels have almost plateaued and the top 4 blowers are very close in overall performance with the slight edge to the big 900 CFM units.
I feel the BR700, EBZ8500, 580 BTS are all very capable and would suit most needs very well.
However I truly believe there's a market for high end models, and people don't mind paying a little extra for them. I can't imagine it's very hard to manufacture, or use a current larger engine, larger blower, larger tubes, to generate big time airflow numbers.
Would it be more $$$, you bet. There are people who use Stihl 880's, Husky 3120's, drive ZR1's Vipers and AMG 63's. Make a big blower and someone will buy it, probably alot more than some think. Surely R&D has a cost but it's a safe bet they would sell...why hold out, we're not getting any younger, leaves are still falling.