Bren, you sound like we'll be critiquing your every move.
Hmm, any maybe i will....
There's nothing serious about how one can listen to these speakers. Personally i would like to hear the GR60s and the Tannoys with a switcher as i know the differences might be quite subtle. I've already heard the Tannoys and the M60s this way and although i could tell them apart, i incorrectly guessed which was the M60 each time. If you're interested in listening this way, or not, it's up to you. I don't have any guns in the house to hold to your head, nothing but a water pistol anyway.
I was thinking you could compare those M3s with my office Tannoys, the Revolution 1s which are likely a bit smaller, but a decent bookshelf quality at least, if you were looking to hear how they sound against another good brand. If we only had some M22s here...but perhaps i can just setup the crossover on the receiver to limit the M60s bass and that might come closer to the tone.
As for the dissertation, been there, done that. A page review of speakers for those interested is a cake walk in comparison. I write about 80% of my living most days so just leave that to me. You just take care of the witty retorts and all will be well.
PS We don't have a bbq yet (threw out the old one before we moved), but beer is always on hand here. Perhaps some nachos and salsa would suffice.