My PTR sounds good suppressed to me but I’m half deaf . It’s still quite loudI have a cetme, their older model (I bought it about 10 years ago). Never had a problem. Their newer model has the rail, paddlemag (but not the metal trigger group) which are a plus. The Cetme/HK/G3 forums have really good reviews on the newer models. You can't have a pretty decent rifle for what the entry PTR gun is.
How does it shoot suppressed? Did you need a thread adapter?
Not really. They just happen to push the most amount of guns (WASR, Galil, Cetme, etc) so their pool of problems is larger than most due to overall volume.
Most times IOINC = junk
Most times DDI = junk
etc