How much do I care about fret size when picking a guitar? Not a bit. If a guitar has jumbo frets, I can play it. If a guitar has medium frets, I can play it. If it has narrow vintage teeny-weeny frets, I can play it. As far as I'm concerned, full re-fret jobs are for clearly worn-out frets. I don't consider it an option like changing string gauge or changing picks. I can't imagine going through life with such an unnecessary, self-imposed burden as having to factor in the potential cost of a re-fret every single blasted time I look at a guitar. If the miniscule difference in fret size or profile is enough to throw a player off their game or make them sound like a beginner, I'd say they need to spend more time practicing and less time obsessing. Maybe try a variety of different guitars along the way.