In my experience it is quite the opposite. I have several GMRS radios. I have some motorola talkabouts, and use an ICOM HT as a "base station" (10 dbd tower mounted antenna). They all work fine.
On the other hand, I also have 4 Boefengs. The transmit audio is extremely low. This is a known problem. Some work, some don't. In order to get usable transmit deviation on GMRS or FRS (which is NFM) I have to put it in WFM mode to have the audio sound like the cheap motorola talkabouts. On 2 meters, in WFM mode, all 4 radios are pretty much useless. Everyone tells me my audio is so low that they cant hear me.
I have tried the "open the microphone hole" trick... it did very little.
The factory is unresponsive.
The dealer ( 409 shop) basically said "what do you expect for $40 bucks?".
I know that some of them work OK, and some of them don't. It is a crapshoot.
Rick