LRP esc´s: SXX TC vs. SXX Competition

[muratti]

I read on the LRP homepage that for 4WD Offroad you should go for a SXX TC esc (which i did) and for 2WD you should take the SXX Competition. The SXX Competition hasn´t got an aluminium air cooling unit as the TC has so i am wondering why it should be better for 2WD Offroad as the TC??? Is it only because of the height? Have 2WD buggies generally less space in height for the esc? The SXX Competiton has no cooling at all and i am wondering if it doens´t get too hot...Please somebody help me
Maybe someone of you has the SXX Comp. and can say somethign about it...