I owned a merc brompton copy which was fine. Except it had all the flaws of a brompton!
Only one I heard cracking was little pixels which was one hell of a loaded up high milage bike. He was not disappointed or surprised that it finally broke. He pointed out that many bromptoms also crack near seatpost tube.
There was/is a lot of nonsence about the bikes being vastly inferior to a bromptom, which is simply rubbish(I owned both bikes at same time). There are a few issues like seatpost slippage that is easily sorted.
From what I gathered the flamingo were impoved over time and had better options like v brakes more gears etc.

I got a new dahon curve for £199 on ebay, and a new mezzo for £389. I am sure you can pick. Up something great if you shop around in usa.