No, you don't want one of those

Wandering around London on Saturday, saw a lot of hybrids with disc brakes. (Not sure if hybrid is the fashionable name for a bike which looks a bit like a mountain bike, but with decent slick tyres for the road, rigid fork, etc). Anyway, thought that was a jolly good idea (I don't get on very well with maintaining v-brakes), so popped into Cycle Surgery in Holborn, and lo and behold, there's the bike I saw half an hour ago, for only 425 quid. Which is easier than wasting time trying to build up some of the things in my shed into anything usable, a state of affairs which is kind of lamentable but never mind.
"Can I try it out?"
"It's too small for you"
"It's a 17 inch frame"
"Yes, that's much too short for you"
OK, I'm a bit annoyed at this point. I like small bikes. I don't want a 19" monstrosity that looks like I'm riding a farmyard gate with wheels at either end. I want this bike.
But no. And it gets worse. The guy at the counter starts asking me why I want disc brakes. Because they're more powerful and they don't wear out as fast as rim brakes. Oh no sir. That can never happen. Disc brakes need just as much maintenance as v-brakes. Which is, I have to say twaddle. Hydraulic fluid doesn't stretch so that your brakes feel sloppier and sloppier as the year goes on, you don't waste years of your life trying to stop them squeal (oh, apart from owners of these brakes) and they feel better. Particularly if you're used to them from all your other bikes. OK, they might in the long term need some maintenance, but the simple fact of the matter is that disc brakes will work consistently without maintenance for a lot longer than Vs. And V's look a bit gash. And it's me that's going to be riding this bike, not the chappy trying to avoid selling it to me in Cycle Surgery.
So I'm sorry Pret A Manger, actually your customer service was quite good. I mean, you even deign to sell me the things I want to buy. Now if you'd just start stocking bikes...