They both suck compared to Harris Teeter.
First of all, Harris Teeter has 1 or 2 "half subs" (about 8 inches) on special every day, $2.49. Tuesday, it's any made-to-order "half sub" for $2.49. So, pick up two and you've got about 16" of sub for $5, not those puny Quiznos/Subway dealies.
Also, friday = any made to order "whole sub" for $3.99 - 16" of sub for 4 bucks.
I also noticed that since they're made fresh in front of you, they are substantially tastier.
If I *had* to pick a chain, I'd go with Quiznos. But I don't bother. They're farther away, the subs are smaller, more expensive, and not as good.