I agree with Mel -- it's a great ballet

(And thanks for the info, rg!)
I saw it several times when it was new, and several times since, with different casts. Like many Ashton ballets, it's lost its subtlety over the years -- more histrionics, more, well, everything. And it's still a great ballet.
Ashton is rarely seen as an innovator, because his innovations are so quiet. I read something once -- I think it was by Clive Barnes, although I've never been able to find idt and may be misremembering -- that you'd go to see a new Ashton ballet and think it was just more of the same, until a week or so later, you realized that there were many new things in it -- new steps, a new way of structuring a work or, as in "A Month in the Country" a new way of telling a story using steps to depict mood and character, or to actually advance the story -- but he's so smooth and subtle they don't look new, and so you miss them.
It's still in repertory -- not every season, of course, but done frequently. Among its many charms was its perfect casting -- another Ashton hallmark.