Spoke to a real helpful Jeep rep today at Chicago show. He has driven both 2.0 and 3.6 in 2dr and 4dr configurations and says both are great. No turbo lag, feels a lot of the improvement is due to the automatic transmission. Could not tell me when 2.0 specs would be available. Confirmed that destroyer gray on the challenger is the exact color as Sting gray is for the JL. He said due to consumer feedback the half doors will still be an option, but will not be available with the openings in the middle of the door as originally planned for 2019.