I'd certainly be interested in the opinion of someone who has actually used these.

I've never had the pleasure of using these preamps, but after reading some almost unbelievably fawning reviews years ago on rec.audio.pro I stopped by the Gordon booth at an AES show and spoke with Grant Carpenter. What a nice guy! And a serious rocket scientist too btw. Build quality is gorgoeus, parts layout is a work of art. If these preamps sound half as good as the hype they're the absolute bees knees.