In my 'humble' opinion, these bikes are nothing extraordinary.
They've average build quality.
On second thought; it's actually below average! I rarely see Sprinters and GD110s on the road, but when I DO catch a glimpse of one; it more or less looks like it had to survive an apocalypse or perhaps a nuclear fallout!
The engine, on the other hand is pretty solid, I must admit. And despite the deplorable condition of most of the bikes I witness, their engines sound pretty 'tight', which is indeed impressive. They don't sound anything like they've loose nuts and bolts rattling around inside the crankcase! They seem to always give you a solid "Purr"!
And the extensive usage of GD and its other derivatives in Quinchie Rickshaws i.e 'Chand Gari' (چاند گاڑی) also reflect the engine's prowess.
So... To summarize:
A solid engine which is unfortunately paired with a poorly made chassis.
Good Day!