as per timetable,12371 is slower but ground reality is this weekly maintains its schedule throughout its journey as it goes via bsb-lko whereas kalka mail generally runs late as it goes via mgs-ald-cnb. so i would suggest u to opt this train if u want to travel.
as for amethi halt,i cant say anything. as both hwh lku sf and jaisalmer sf has only10-15 halts enroute. so removing any halt would nt help in speeding these train.