Seemed pretty decent but nothing spectacular to me
I've both defended and derided the R51 a lot, but I will say this;
The gun is selling for like $450 dollars, right? Temper your expectations with that number in mind. $450 all-metal 9mm autoloader. It won't be a Wilson, I don't think even the budget Remington 1911's sell as low. The next step down are all polymer or zinc based.
So if the quality/execution still falls short of what is acceptable for a $450 pistol, be mad, say nasty things online. But if your main quibbles are quibbles like the surface finish or a few cheap plastic parts (grips, trigger, mag baseplate), well, it's a $450 handgun that can shoot 9mm +P; find me another that's significantly nicer.
Just trying to keep people from getting their hopes up unjustifiably
the R51 fits my hand really well
It certainly has the best hand-feel of any pistol I've shot to date, and as cliche as it is, the thing seemed to "point naturally" after the first dozen rounds I shot. If it sticks around, I may seriously look into exploring my concept for a grip-safety-activated integral laser sight, and making replacement barrels.
TCB