True shift max / Speedblade XS holders

When going from shift max to speedblade xs holders of the same size , do they have the same hole pattern or do new holes have to be drilled. Thanks

New holes will have to be drilled. True holders are symmetrical whereas XS holders follow the same hole pattern as Lightspeed Edge holders. 

Do the shift max holders / runners , have much of a different feel than  tuuk edge / speedblade xs / stepsteel , holders / runners ?

They are stiffer and from my memory taller. If you want to take the time to get used to it it shouldn't take that long, but for a lot of guys it's just easier to swap

The profile of your steel will make all the difference. If you get the same profile that you've had on all your old runners, it'll be much easier to transition from your old holders to the True holders. 

I never do the profile. I'm going to try out the shift max holders , they came with the DLC runners. I like just the stainless steel runners , so I ordered  JRV shift max stainless steel runners from B - Sharp. We''ll see how they feel.