Yeah, heavy strings make a big diffence.
Especially with a heavy guitar.
Magnets age too, less pull on the strings, among other things.
Also, a guy brought his '64 strat up to my place about 5 years ago so I could "try before I buy", through my own amp.
It was a transitional 64, with veneer rosewood board and pearloid dots.
I just didn't like it. Sounded dull, no mojo, and the board had nearly worn through.
Not a patch on my old 64. (If it hadn't been molested by that f@#$%^*$##, my search for tone would have ended right there).
I checked out two strats at a shop in Brisbane a couple of years ago, both 68's.
Both burst's, but both completly different.
One was muddy n nasty, the other soft n sweet.
As you know, the p/ups were wound with differing amounts of winds back then, and some were hotter than others, maybe by mistake, or by design, I'm not sure.
The price was way too steep, but I nearly bought the muddy n nasty one.
Its one of the things I like about old strats, they're all different.
Not necessarily all good though.
I did some work (set up) on a friend of mine's late 60's firebird with p-90's, and I played it through my rig.
Man you should of heard it sing through my Chandler pedal.
Rocked way harder than my strat.
I begged him to sell it to me but he wouldn't part with it.
Not as versatile as my strat, but it would have been killer for
slide.
I really like the clean tones of a strat for slide though.
Wish I had the bucks for both a Gibson and a strat for slide, but I couldn't even afford to restring em all lately.
I used to take 3 guitars to every gig, a '90 butterscotch Tele for Spanish, Strat for Vestapol and Strat for standard.
Cost me a freakin' fortune in strings, and became too much to lug, so I eventually sold the Tele.
The Tele rocked for Spanish(A or G) tuned slide, sometimes I wish I'd kept it.
Had that DBX tone control.
I seen a sweet little LP junior with a p-90 at a second hand shop in Tweed Heads.
I never got to buy it, but I wanted to. Cheap as well.
I bet they really sing with a slide.
Your right about price and value.
I set up a few Squiers for slide for some of my students, and A/B'ed them with my '78.
Had me going for a while with one of em, I was about to trade in mine for a Squier.
I spent hours, nearly went crazy, but my '78 finally won the battle.
Not by as much as I would've liked though.