One thing is the XT-70 has only factory small coils the biggest about 10.5". The MXT has aftermarket coils that are HUGE for covering more ground while prospecting and relic hunting. Like big coils from Jimmy Sierra and SEF. I prefer the XT-70 over the MXT as a close call because of very light weight and some features. But those BIG coils for the MXT are attractive....and if you NEED them buy a MXT instead with a bungee cord.
Don
Don