Test set up as described in this thread here, with an exception that I'm using two FaTip Grande Open Comb razors this time, one in gold finish and one nickel plated. I'll refer to them as "Silver" and "Gold" coloured for this test...
This test compares the two varieties of Gillette 7 O'Clock Super Platinum blades - the "Black" package ones from India against the "Blue" package ones from Russia.
Gold = right side of face
Silver = left side of face
Brush = Simpson Duke 2 best
Soap = MWF
AS = Geo F Trumper Limes
Pass 1, WTG: I noticed an immediate subjective difference - more audible feedback from the Silver and more of a "suck to the skin" sharpness feel, with the Gold being quieter but feeling a bit smoother. I had 3 days of growth, and both got through it with ease. So first feeling is that Silver is a bit sharper, but Gold is a bit smoother - not much in it though.
Pass 2, XTG: Felt less difference on this pass, with a bit of audible feedback from the Gold bring the two closer together.
Pass 3, ATG: Both very efficient - equally so. I did get the feel again that Silver seems a little bit sharper, and Gold a little bit smoother, but I really can't be sure how much difference there is at this early stage. Noticed a very small weeper on my chin from Gold and a tiny one on my upper lip from Silver - both stopped very quickly.
Closeness: Very close on both sides - can't really tell any difference.
Comfort: Felt nice - had that "just shaved" feel, but with no irritation.
AS: Bit of a sting from the GFT Limes, but I think that's to be expected - it left my skin feeling tight and very clean.
I've used the Black blades before, but this was my first time with the Blue - it's clearly a very good blade, but on this first shave they do feel a bit different.