Dave- maybe we can put our varying views on this musician down to taste, and I've never been convinced by arguments best summarised as 'well everyone else liked it', but I'll try & clarify my views.

It's hard to justify a feeling but his virtuosity was to me anathema to the whole ethos of folk music. Partly because he obviously had a high opinion of himself- I heard him murdering his party piece, the 'Mason's Apron' with increasing speed, wildly inappropriate variations, purely for the adulation of his admirers, who seemed to put virtuosity above all else?
I heard him once and it was enough for me. During a lot of the 70s, I was in London, listening to the Irish in Holloway, Fulham & other places, and it was a pleasure to hear the understated, self-effacing and community-based music of Bobby Casey, Jimmy Power, Liam Farrell & Raymond Roland, so maybe we have different ideas of what the music is about?
   I have no wish to turn this into an argument about Sean Maguire, nor have I any idea why great musicians liked to play with him (JohnDoonan was a great admirer) maybe he was a technical challenge?