Just for the background, i grew up in Quebec city until i was 25, then moved to Montreal for 10 years, went back to Quebec for 4 years and moved back to Montreal a few months ago, probably for good. So i know both cities quite well.
While both places have their charms, Quebec city is more calm in every way, less urban more subburban i would say. It's not a default, but that's a fact. Escort-wise, you will not find lots of agencies with extensive rosters in Quebec city like you do in Montreal. I used to deal with Aphrodisia, they had some great girls, but they closed last year. I think they've been replaced by O-Sense or something like that. There is one incall place where you can walk-in, but it's in the middle of an industrial park with nothing around, kinda shady, i don't recommend it.
The indy scene is quite limited when looking for sure value. I met a few great girls during my time there, but most of them disappeared after a while or were awfully hard to book because of offer vs demand.
I have good memories of some encounters with great early/mid-twenties girls, but overall it's much easier to find something that suits your tastes in Montreal, if not overwhelming at times.