I have seen some interesting photos on the MTBR forum where they have a twist/grip shifter for the front and a trigger shifter for the rear. This makes sense to me since it does require more effort to shift the front into a harder gear and, for me, I have more thumb issues with with left and hardly any with my right. If it turns out that a twister is easier on my thumbs this might be a good way to go - especially since it sounds like twisters are friction and not indexed - it would be nice to keep the indexing for my rear cassette...

Has anyone here mixed shifter styles in this fashion?