Crew Acceleration: Worth It?

__WarChild__, on May 01 2018 - 14:42, said: Howdy Tankers,   After about 5,000 games, I finally realized that Crew Skills were pretty dang important especially 6th Sense.  Since that time, I have been selecting the Crew Skills Acceleration option on all of my tanks.  This means that when they have the Free XP conversion specials, I have very little (if any) XP to convert.  Now I'm wondering if the math is good on selecting that option or am I getting little in return for giving up a lot - i.e. accelerating my tank grinds through the cr_ppy tanks. 
Would like to know what you think is the right move here.   Thank you for your time.   __WarChild__