Lownslow,
I was flying the M18 T45R, which is the dromader with the PT6-45R motor. The dromader is a fine airplane. It was the eastern block production of the thrush, origionally. It's bigger, hauls more, has a better wing, and I think, is a better airplane.
This particular drom was heavily modified, with changes to all systems. It had different brakes, fuel, hopper, instrumentation, engine, and mods to the structure such as lengthened stinger, etc.
The Dromader flight and maintenance manuals are the only one's I've ever reviewed that were prefaced with the statement, "Nothing in this manual should be relied upon, or believed."
That says a lot.
Simply because they're low cost doesn't mean they're substandard, however. It's worth noting that a lot of very expensive air tractors have come apart...a friend of mine was killed in one last year. Three droms have lost wings, all the result of people complying with the wing attach fitting AD, and then overtorquing the fasteners.
It's also worth noting that in each case, a wing separated in flight, and the pilot walked away. There aren't many airplanes that this can be said about.
I was hauling 600 gallons in the airplane at density altitudes approaching nine to ten thousand feet and higher. That's just the departure...the airplane did just fine. I was dropping above 12,000 density altitude, and the airplane did fine.