I don't have any experience with the Lauf GRIT, but I do have experience with the Lauf that I had on my Lynskey that I used quite a lot on gravel. I guess the real difference was the 30mm extra of travel and obviously mtb tires but also 40c MSO's. I also have used the RedShift Briefly only because I spotted on someone else's bike and rode around for a few minutes.
I believe its fair to echo that they're objectively different. So the Lauf on my MTB was really good as long as I was in the saddle. It actually tracked better than some of the best air forks on the market. Out of the saddle meant most of the travel was consumed under my weight. The only time I found this to be good was climbing, it climbed really good and you could feel the bike surging every pedal stroke without the lag of fork squat.
To me, the RedShift stem really felt like it was meant to isolate the bars/hands as a contact point. When the bike hit a bump or really anything that wasn't smooth, you'd still feel it in the rest of the bike, but it was a bit more muted in the handlebars. The Lauf would actually absorb bumps entirely until that bump made it to the rear wheel.
One of the biggest differences which for some reason people don't consider, and maybe its more of a problem where I am with the constant coastal winds on open unprotected terrain is aero. For some reason, the fork seemed to catch more wind than even the SID team fork. I don't know if the GRIT is different/better in that regard.
What I do know is that Lauf just released the True Grit bike which has a "GRIT LS" fork that's shaped different and suppose to be lighter and laterally stiffer. Lighter is always better, going to a Lauf fork meant adding about 1lb of weight to the bike, the RedShift stem....slightly less than half that.