just my 2 cents on it out of the 5 vehicles i have owned 4 of them have been manuals, only one that wasnt was my full size silverado, and both my JKs have been manuals. The 2 vehicles i currently drive is my DD manual Tacoma and my 12 JK 2dr 6 speed. the clutches in both my jeeps have always been light and seem springy (best way i describe it) especially compared to my tacoma which has more of a hydraulic torquey feel. I guess im one of those rare millennials that can drive a manual and while searching for my Tacoma and JK it took me over 4 months each because i specifically wanted the manual, i even turned down a price match with over $2500 options extra on a tacoma because it was an auto and the guy at the dealer thought i was crazy but hey i like what i like and didnt want to settle. So if you want the manual Go for it! :rock:
since you are looking at a rubicon with the 4-1 tcase, i also had an 08 Rubi and i swapped in a rubi tcase into my 12 sport, in 1st gear and 4lo even though the clutch is springy it still has plenty on the low end torque. Biggest thing i have going against me right now is the 3.21 gears in my sport so if you re gear to match your tire size better or go with the 4.10 option in the rubicon i really dont think you are going to be disappointed with the low end in 1st lo even though the clutch doesnt feel as good as the TJ.
as far as the hill start assist goes since i have had the 08 without it and the 12 with it, personally i could take it or leave it. Its more of a novelty and is kinda nice to have for every day driving on the road, i leave mine turned on and really i didnt notice it much on the trails just because im used to not wheeling with it im fast on the clutch and in 4lo with the 4-1 the torque kicks in so fast that maybe it helps but i really couldnt tell ya. I havent gotten into the big rocks yet with my 12 like i did with the 08 so maybe at some point it will help out but you can also just use the E brake trick.