I have built from a few of Don's plans. Never had any problem at all. I found them very easy to follow, with common sense built in.
I talked to Don a few times, and he was always there to help out if needed.

Scratch building is indeed going the way of the almighty dodo. The overall costs of very large projects is definetly a big concern.
Don's plans are all big, so obviously be ready to throw in a few thousand to get one of these biggies in the air.

You have to ask yourself right from the start, , , , how much are you willing to spend.