We always take 72 off of I-10 at exit 45 when going to Parker, the river, Lake Havasu, Laughlin etc.. Will do it again this month on our way to Buckskin Mountain SP.
Staying on I-10 to Quartzsite and taking 95 north adds miles and traffic, nothing to be gained there... both routes are mind-numbingly boring and ugly.
As always... Opinions and YMMV.
:C