Hello Doug ,
Having a Whites 50Khz machine I would lean towards the MXT for the simple reason you will be digging less ghost signals.
I've used a mates Tesoro Vaquero its 14.3khz , has a prospecting mode , easy manual GB , also has great discrimination for trash areas , light weight ' about 2.2 pounds.
And it signals good on nuggets

Tesoro have a life time warranty ! Not like some others .
Cheers Bobby.