You can probably find mild in Warrington but I would not drink it even if free.

Tulip, straight or nonic glass usually.Served in a coconut, I assume?
A few pubs do that to show you the beer colour. You can also ask for a taste sample in most pubs.Is that sample to help know what you're buying?
I've come to the conclusion that I'm not really keen on nitro beers myself. I drink a Guinness once in a while but it's a pretty dumbed down drink these days I reckon. Not much flavour. Cask is my preferred serve, but I just bottle my homebrew, I've stuck with what I know. I make small batches and I like bottled beer.I always wanted to try this recipe on cask. I have a nitro tap, but have never tried it with this mild. I normally only carb my British ales to about 6-7psi. Cask is not much of a thing here in the States.