I think that most wind generator enthusiasts are enthused without much information on how they perform in the real world.
The curves of the Superwind 350 and the D400 show pretty much the same output vs windspeed up to 25knots.
They are similar in design - both 3-phase axial generators.
At 15 knots they both say they produce about 3A at 15 knots and about 7.5A at 20 knots - 24V - see attached.
The Superwind levels off at 25 knots / 14.5A output due to its auto feathering system. The D400 keeps going at higher wind speeds 20A @ 30 knots, 27A @35 knots.
Of course, all these numbers are assuming a constant wind speed from a constant direction..... a luxury ideal that we rarely see.
And that confirms my previous comment, the only time I ever saw useful output from our D400 was heading up wind in 35+ knots, but I wouldn't pay wind generator money just to have that experience!
In general terms, under most conditions, it seems they don't put out much at all and the kW/$ equation just doesn't add up to me.
Still each to his own. Belief seems to be as important as evidence these days in some quarters.