I did exactly the same as you when I started out with my Karve. Now I like the "D" OC plate best of all, but also enjoy the "D" SB. The "E" SB & OC work well for me, but require more attention.I have only used the Karve and 6s. Of the two the Karve is the clear winner for me. Its design gives it a great glide (SB and OC) and it's one of those razors that I just enjoy using. I suspect a combination of its weight, handle length and plate design make it very smooth for me on the ATG shave using any plate.
When I started with the Karve I used the C SB plate. I ordered a B OC plate and found that was too mild. I have since ordered a D and E OC plate and am using a D SB plate until they get here.