Sadly ATC only claim to make the world's most accurate reference loudspeakers. Everyone else makes monitors.
One of their more level headed claims is that they produce loudspeakers of a quality far above the industry norm. No issues there, have you heard the industry norm?
On a serious note I'm sure you will have a great time in July and play some great music. Sadly from my point of view, Scotland is a bit far to travel to hear a loudspeaker I know I am not a great fan of. Now if you had some TAD's or big JBL's that would be a different story!
This last week I had the pleasure of listening to Bottleneck's new Altec Valencias. These originate from the same era as the ATC's (mid seventies) and provide a quite extraordinarily different presentation from that foisted on most listeners today. Dynamics were quite scary on those horn loaded beasts!