I only go to Martin's concerts where no-one else is billed, so tuning-time doesn't bother me, and he always fills the minutes of ying-yanging with interesting anecdotes and mind-boggling noodling, which I'm happy to listen to.

I agree about tuning into an open tuning being easier than t'other way round. Might it be because open tunings are generally lowered, whilst going back to standard means raising string pitches?

The only problem I run into with lowered tuning is in DADGAD, where getting the open 'a' to ring perfectly in tune with the second-fretted 'G' string can be a bit frustrating. It happens on all four of my guitars, so it's not a problem with an individual instrument, I suspect it's more likely a touch of tin-ear on my part.

Gerry - I should be there. I might bring the new toy - my mandolin - don't forget your earplugs! 😜