Restring Time

Locking tuners on a top-loader Tele. I can do those super fast.

I feel rather strongly that being in the habit of changing strings often is superior to finding a set of strings that lasts ridiculously long. The super long lasting stuff is fine for guitars that spend a lot of time in a closet, but doesn't make a lot of sense for guitars that get played. It is often the same price wise.

^ This ^

Strings that keep their tone longer will stay on my guitars long enough that normal wear and tear can lead to breakage. Once I realized that, I knew I'd rather change strings sooner than have one break when it's inconvenient. When I was gigging and studio-ing, that decision was pretty for easy for me. For home players, they may never care.

Re: the OP, 8 minutes is excellent! Anything under ten minutes qualifies as fast.

I once broke a string onstage in the middle of the opening riff of a song. MIJ strat, floating vintage trem, vintage Kluson-style tuners. I shouted a quick "keep playing!" to the band, had the old string off and a new one on and stretched in in 90 seconds flat, just in time for the guitar solo. I got a round of applause for that one! Still in tune at the end of teh song too! 

Yeah, strings going dull is only one part of the equation. I have one client who plays very frequently (5-6 nights a week, solo acoustic) and very hard, and I finally talked him out of wasting his money on Elixirs. He would wear off the windings at the frets (he has stainless frets because he plays so hard), and whenever he broke a string, he had to break a set. He was changing strings at least once a week. Total waste of money.

Then, there's intonation. I get the sense strings don't lose their intonation as fast as they did 10-20 years ago, though. When I was playing more frequently, that is usually what I noticed first when strings died. I'd play something like an A at the 5th fret, and it would be impossibly out of tune, but in tune open and at the 12th fret. Now, I can take a guitar with old strings, set the intonation, put new strings on, and when I check with the new strings it isn't THAT different. Perhaps there have been improvements that I'm unaware of.

Part of the popularity of coated strings is that Taylor "recommended" them, and people took that VERY seriously... as in, I would semi-frequently have people convinced it was bad for their guitars to use anything else. They're great for guitars that just sit - sitting in warehouses, on shipping docks or on showroom walls is a PERFECT environment for a coated string. It is hard to sell a guitar with dead sounding strings on it, so knowing it is ready to demo is a real plus. Some players are like this, too. The guy who has 8 electrics and only breaks out the acoustic once in a great while for a backing track on a power ballad... he's almost guaranteed to have fresh strings when he pulls it out with a coated string.

i can change a broken string durring a song live

Probably all of those, but my money is on whatever machinery they have for putting on the windings.  As I understand it (and mostly a guess), the intonation goes wonky because the string has uneven density/mass/diameter across the length of the string.  If the windings are bunched up too much in one place, tighter in one place than another, or loosen/shift in some way, your intonation goes out the window.  It is like moving the frets around mathematically, you're just changing a different variable.  You can definitely imagine string company X having the old machines they've had since the '60s and finally upgrading in the 2000s or 2010s to something better and fixing these problems along the way.

I've never visited a shop that makes strings, so I'm mostly guessing, though.

Restringing is not a big seal for me except for guitar with a Bigsby. which definately slows me down.