Not sure if this would be applicable or not but I recently replaced the single handle shower faucet in one of the bathrooms in the house. It seems that all the new faucets come with a "mixing valve" that restricts the amount of hot water that can be mixed with the cold (the nanny state at it's finest I guess...
). It sounds like your faucet may have this feature which would explain why the shower doesn't get as hot as other faucets. It can be adjusted, to a certain point, by removing the cover and moving the mixer towards the hotter setting.
TT: 2015 Jay Flight SLX 195RB Baja Edition
TV: 2014 RAM 1500 Big Horn CC, 5.7L Hemi, 8-spd, 3.21LSD, Factory Air Ride/Tow Pkg, Andersen WD/SC