Quiznos had amazing quality when they first opened but it dropped when they tried to compete with the subway $5 footlong deal. They should have differentiated themselves as the premium sandwich brand because while subway is pretty good, Quiznos early on was a whole other level. Me and my housemate at the time used to go there and order 2 subs, one for now and one for later (that often worked out to be right after the first one was done, in practice).
There were some locations that stayed open around here for a like a decade after, but it was always disappointing going there. They were still better than subway but only marginally.
I like Firehouse Subs these days. Not quite as good as Quiznos at its peak, but closer to that than Subway (which was always better than Mr Sub).