Great devices and long lived but if you acquire an older one beaware that you are probably going to have to have it overhauled and recalibrated - being essentially a lab instrument electronic maintanence is more a a necessity and since it's a mechano-electronic instrument there is much, much more built in "Murphy" than the newer ones (whether you like them or not I bet the newer ones will far outlast the older one - with the caveat if they are "too cheap" then all bets are off).
If you're lucky enough to find one that's worth restoring/recalibrating send me an e-mail cuz I know someone who'se been doing factory field service for decades and one of the best overall electronics techs I've ever corresponded with. I'd trust him to restore one before I'd trust the "youngster" tech at the factory who probably wasn't born when the instrument was made.
So what's the beef with the Peterson tuners? I love 'em to death, they're incredibly accurate, etc. In fact, I usually just use mine for really "picky" fine tuning, favoring the run-of-the-mill guitar tuners for most set-ups....because the Peterson is TOO accurate and drives me crazy trying to line-up everything. Truth be told, I always start with a pitchfork and take it from there.
I can't tell there's anything wrong with my blue Peterson VS-1 (or VS-something) in terms of getting as exact as you like tuning the fundamental and harmonics. In everyday use (as a guitar tuner, not intonation gauge) it suffers from being a little show to update or settle down at times and it is too bulky to fit in my guitar case. But the actual operation of it is as flawless as any tuner could be.
It certainly brings home the old adage that a fretted string instrument is never in tune with itself. All those little minor intonation errors that people with really good ears can detect on various strings at various frets are right there in front of you with one of these tuners. You certainly can't convince yourself that any guitar's intonation is "perfect" at any moment in time.
P.S. I should say "acoustic guitar" because with a Telecaster with six individually-adjustable saddles and light strings you can dial in a pretty good shade of "perfect".
I don't know exactly what it is about the peterson. I think its just the horrid blue display. Its hard for me to see. I don't like the "action" of the thing. I know that they are a well built, accurate tuner. Just not my cup o' tea.
My moms got one in her school room(music teacher)... maybe when she retires I can convince her to swipe it for me.
The display on mine could definitely stand better visibility but I must say reading the dial on the mechanical strobes is even harder. But overall I think the advice given here is good, owning one of the old mechanical strobes is like driving a British Leyland convertable. It's very cool but you're tethered to a balky, maintenance-intensive stepchild.
I just bought a Planet Wave stomp/stage tuner with the circle display. Tracks very fast and the display reads great in most lighting. A friend has the Korg rack mount with the big arc display. That one seems like a great bench tuner. Those old Conn spinning deals used to give me a headache. I now use the V-Sam. Love it!