Right so the considered views is Ti has no impact on rideability whatsoever? If that's true its wasted inside a S6R/Schlumpf build, I would be best keeping the Ti inside a M2L.

I'm doing my blind test possibly as early as the weekend, ordering some Ergon GR2-L next days, S6L vs S6L-X.

Right now I have 3 Brommies configured S6L/BWR, S6L-X/SRAM, and M2R-X, and a Schlumpf Mountain Drive. My plan is to make either a S6R-X/Schlumpf or a S6R/Schlumpf for long-distance touring and the question is purely impact on speed and comfort.

I'm definately keeping Ti on a S6L-X/BWR. So the fallout is do I end up with a M2L or a M2L-X.

There's something inside the Brompton making it slower, I average 2mph slower than the cheapest REI 27speed Alumium $600 bike I have which does most of the mileage. I'd prefer to use Brompton for flexibility of folding or riding to a more distant place to get the bus back but not at 2mph slower.

From what you're telling me, the Ti vs Steel will have negligible impact on performance so I might as well keep the Ti on a 2-speed where it will do the most good (carrying weight). Hopefully by this time next week I'll figure it out because I have to do an evening of parts shuffling to get to the 3 end configs. I need to move the BWR to Ti soon, the chain droops onto the frame when freewheeling on high hub gear, it will for sure ruin the paint if I keep it on the steel frame and I need to move it over and ride it to break-in the BWR and get it more efficient before I then rely on that bike as my regular day bike.

FYI, I picked up in the Brompton dealer the Steel seatpost vs the Ti seatpost - the factor of 3x on the weight is very noticeable.