Again, I meant the Performance Center 1911 not the service grade.
I don't think one is going to be measurably more accurate than the other.
They both will be VERY accurate handguns
The advantage of the PC1911 is that if the grips do no fit your hands well, you can adjust to slim, palmswell, or normal grips, and have a selection of several materials from wood, to rubber, to laminated linen of micarta, to aluminum, etc, etc. If the trigger reach needs to be adjusted, any gun smith can handle that. With the 945, you really have a selection of the grips already made and a few boutique makers that do limited or custom runs.
To me, the 945 is a showpiece of the performance center. An entirely unique design where they could apply their craft to the maximum of their ability and offer a "dream" gun. It's the last home grown project they did before converting over to 1911's exclusively for autos. It really is a hybrid of a third gen auto and a 1911. But the 1911 and especially the PC1911 is a true workhorse that not only gives you an outstanding starting place, but allows you to grow the pistol's features to meet your needs as they develop.
As mentioned before, either will do their job in spades while remaining desirable and reliable. The PC1911 will simply give you more options and support.
I might be stepping out of my area of expertise, but I at least thought that the 945 was fairly ammo-sensitive regarding accuracy, (meaning super accurate with a few bullet weights and loadings, accuracy falling off with others) whereas 1911's typically are accurate across a wider selection of ammo. This isn't based on personal experience but rather from hanging around the indoor bullseye league and reading the forums here. No problem if someone corrects me on this last point. I know that the 952's would open up on heavy ammo.