Tried the 0.68 which is very nice for daily shaves but since I shave every 3 days I opted for the 0.84 which gives me a bit more efficiency
Some of the fellows have also bought the Game changer open comb .68 gap and like it also. I have a RR GC .84 is really nice shave, I like the KAI blade paired with it lately and it is a nice shave.
Use the .68P as a daily shaver. The .84 OC I don't find to be as comfortable as either the .68P or the .84P. Many seem to like the OC version better.I have the Gamechanger .84 OC and I love it, so far might be my top razor, I have zero doubts the .68 is also an amazing piece