To sound AND feel.
When discussing gear, when looking at product descriptions, when watching reviews and demos -- You'll hear lots of hype about pickups, about bridge hardware (I so often hear people saying the telecaster signature sound is due to the bridge design), about wood type, about fretboard.. But people don't usually talk a lot about scale length. You're more likely to hear someone say that the maple fretboard you might have on a stratocaster is what makes it sound bright, or about the bolt on neck making it sound snappy, (hint: set neck and bolt on neck mean absolutely nothing to sound) than you are to hear about the scale length. Most people around this forum probably know what scale length means, but I think they under-attribute its importance and over-attribute the importance of just about everything else.
In the last five years I've been pretty much a full fledged, mouth foaming, buying, selling, trading, never happy gear hound. I've gone through every guitar archetype and played the whole aftermarket pickups and bridges game. I've done it all. While I've always been in the skeptical camp about wood and pickups (obviously pickups sound different, but it's definitely overhyped and over attributed), I have gone through some evolution in my gear head years. I'm still a gearhead who loves gear for reasons ranging from the practical to the "just because", but my baseline view about what's REALLY making something sound and feel the way it does has really solidified.
Pickups matter. Electronics matter. Wood/fretboard type -- I'm not prepared to say it matters much in an amplified, signal processed world. We may have to disagree on that one.
But what matters absolutely the most of anything in defining the core characteristic of the guitar? The core sound and feel that everything else is built outward from? It's the scale length!
There's a reason strats/teles sound and feel so characteristically different from les pauls and sgs, and it's not the pickups or wood or bridge. Those things matter, but those aren't the SOUL of the guitar. The pickups can be easily changed. If you put a single coil into a Les Paul, that doesn't make it a strat. And they absolutely make humbucker equipped strats and teles, but they still don't come off as les pauls. And it's not the wood or bridge or the neck joint type. It's the SCALE LENGTH!
I know you guys know abhout scale length, but I really get the feeling most people are underappreciating just how transformative and defining this measurement is.
25.5 scale length (strats, teles, jazzmasters, and copies): Plucky, spunky, spanky. Aggressive pick attack.
24.75 scale length (gibson/epiphone stuff and copies): more laid back, more slinky. Neutral, unoffensive
24 inch scale length (jaguars, mustangs) rubber band guitar. You can HEAR a 24 inch scale lengh coming through the amplified tone even if other people are playing. You can HEAR those 24 inches coming out of the speakers. The pick attack is just so dramatically different sounding. You can hear it even through distortion.
There's no mistaking it. You can change pickups all day but nothing is going to change the scale length of your guitar (nothing reasonable, anyway) and that is what that guitar is. Stop kidding yourselves about everything else. This is the main thing that matters when choosing what type of guitar you want. This is the SOUL of the guitar.