I was surprised how nice a golden delicious apple could be when grown
slowly on a dwarfing rootstock and ripened on the tree. The pumped up
water flavoured supermarket things are nothing like a home grown one.

I think that's spot on. I haven't eaten a fresh Golden Delicious, but
you aren't the first person I've heard say that a just-picked GD is very
good.

Another apple like GD is Greensleeves - I think GD was one of the parents.
Greensleeves has very similar appearance, a thinner skin and, in my
opinion, a superior but similar taste and texture.

I would recommend trying Ashmeads Kernel. It is a half russet apple, with
(if I remeber correctly) Cox OP as one of its parents. Very late ripening,
and to be its best it has to be ripe, either kept in storage on on the
tree - at least that my experience up here near Wakefield.