That's a hard one, as you say the blades are different and I've had success with razors like the brass General where you haven't so making a comparison to other razors won't help you much.......all I can say at the moment is with the blade I've been using its a Very Smooth but also a very Efficient razor, clean in two passes, and a buttery smooth finnish.
Now I have not used it with the SS Gem blades yet so can't comment on those but I am going to use one in a couple of days so will be able to tell you then. I am shaving with the Sabre for a full 7 days in a row so I can get enough of a feel for it so I am able to write a reveiw regarding the razor and the different blades I will be using. It's too early yet but I could stick my neck out and say this may be my best razor I've had yet.....but as I've said, It's a bit early to say for sure, the General fitted with a feather super is very efficient but perhaps not as smooth as the Sabre. I agree it is one stunning looking razor and for me even after only two shaves I would say it shaves as good as it looks!
I hope this has been of some help Rob.