Some excellent points made so far, and here are three with which I agree wholeheartedly:
1. (Thanks to @Cork-All-Star ) There is no way that both Arkle and Flyingbolt, while undoubtedly brilliant, were twenty pounds better than any National Hunt horse of the last sixty years.
2. (Thanks to @LD73 ) Istabraq was overrated (name one top-class horse he beat).
3. (Thanks to @TheTinMan87 ) The bloated behemoth that is the current Cheltenham “festival” is ruinous to the winter game.
By the way, a close fourth was @graysonscolumn ‘s assertion that Sir Peter O’Sullevan was overrated; I put Sir Peter’s longevity down to what I call “Richard Whiteley Syndrome” – he’s been there since the year dot so, no matter how crap he is, he has a job for life.