Ultimately, of course, the real question isn't whether an amp is hand-wired, printed circuit board, or made from moon rocks.
The important question is, "How does the amp sound?"
Back to Les' original post... In my experience, I don't have any amp that loves every guitar that I have, and I don't have any guitar that loves every amp I have.
It's funny, thinking about this, I'd say that the three amps I have sound quite good with all of my guitars. But it becomes a matter of some of the combinations simply being magic. Perhaps that's where the "love" part comes in.
However, magic is one of those "that depends..." kind of things. It isn't always guitar plus amp. Example:
I always disliked a Strat into a Plexi or plexi style reissue Marshall. Just wasn't a tone I liked, thin single coil into Marshall. But then I did a gig with Laurie Wisefield, who's toured with Clapton, Joe Cocker, and been in Wishbone Ash, etc. His thing was a '65 Strat into a Marshall JTM45 Reissue. However, he always had a compressor pedal on to thicken and boost his signal. And being Laurie Wisefield, he sounded phenomenal - beautiful tone, great playing. So he used an extra tool, added his own skill, and simply made the combination work extremely well.
So that was magic, only he needed an assist from the pedal. Well, so did SRV with his amps. So did Hendrix.
I like it better when I can plug a guitar straight into the amp, like I can with a PRS, and then take the flavor further with pedals if that's what I feel like doing. That magic trick thing of course is a little harder without tone shapers like pedals, unless the unadorned amp/guitar combination is a good match. And of course, each guitar has its own resonances, electronics frequency response, and accentuates certain frequencies, and those frequencies either work very well with what drives the amp into heavenly tones, or not. It's like certain voices being magic with a certain microphone, and others, not so great; this is something I've seen over and over again in my studio.
Put a great female singer in front of an AKG c12, and I'm in love. Replace that mic with a Neumann U87, and I might like it, or I might want to shoot either the mic or the singer. OK, better to shoot the mic than the singer, but you get what I mean, especially if she's an alto. In any case, it's not the mic, and it's not the singer. It's the combination.