I have visited the local HF store and the Grizzly showroom in Springfield and seen the machines on display. I have also purchased several Grizzly machines, both for myself and for my employers.
My main observation is that, yes the basic machines are very similar, BUT the difference in quality is obvious. I suspect that HF places an order for machines from a Chinese factory and accepts whatever they ship to them. Grizzly has much better QC on the orders: I don't know how they accomplish it, but they do.
So you are paying for a better quality machine, even though the basic design is the same. Also, the more expensive models often have features that a less expensive import may lack.
I suspect that the smaller importers are probably all over the map as far as QC is concerned. But most are likely in the same boat as HF.
Make it fit.
You can't win and there is a penalty for trying!