True - my parents wax lyrical about a cultivar called Howgate Wonder, which they used to buy from a local orchard long before I was born. I have never seen them for sale myself and consequently haven't had the opportunity to taste them. The orchard still exists, reportedly...

I have departed British shores as of a few years back now, but I understand that a lot of the varieties really only exist in various national collections these days rather than having much commercial growth. There are significant growers of less usual cider apples, not that they'd be great for eating. So how you actually get your hands on them ... ?

There do seem to be online shops that'll sell you a tree from many different strains though.

As with many things, the supermarket optimises for storage, shipping, uniformity etc, and in the end we all miss out on variety. It's even worse for that here in Australia - there are precisely three types of potato - red, white and purple skinned, and they're all much the same and pretty bland. There's a fourth 'gourmet' type (kipfler) allowed at really fancy stores.