My 2017 CU24 piezo (and my 2013 P22 stoptail) is thicker than my 2015 CU24, but doesn't seem quite as thick as my McCarty 594.
Both piezo models are awesome, highly versatile guitars. A lot of times at band practice I only play my CU24 piezo, I can be lazy because it will cover everything in our setlist without having to swap.
Can't speak to how much TCI or the new finish will improve things. I can't imagine it will be so dramatic to make me want to spend big bucks to upgrade.
Edit - my two piezos are on the right.