Pros: The Herco Peg Winder is more stable on the peg than other brands
Cons: Only accepts guitar tuners, not bass. A GOOD THING IMHO!
I have been a professional guitar tech since 1977, and my Herco peg winder has been my main winder since then. I restring more guitars than anyone you'll probably talk to as I work in a busy guitar repair shop, and have for decades (I once restrung a shippment of 100 guitars in one day... my all-time record... I CRANKED!) I actually had two Hercos and lost one recently, so I'm real glad to see Herco still makes them as I want to replace the one I lost. This is what led me to doing this review (I realized how valuabe my trusty peg winder is to me).
The Dunlop and Planet Waves peg winders, which are argueably the most popular peg winders out there, don't work for me. Some models even have built-in cutters and electronic tuners, but they just don't feel right. They are too loose on the peg, and lend themselves to "wobble", whereas the Herco peg winder is MUCH more stable when cranked. I believe this is due to the multi-use head designs on the Dunlop and Planet Waves- they're over-engineered to fit onto too many types of tuner knobs. They are also made from high-impact hard plastic that can marr the headstock wood or the nickel or chrome finish on die cast tuners. The Herco, at least mine, is made from a softer plastic that is durable and does not marr.
So you know I'm serious about peg winders, I am currently in communication with Planet Waves to have them make a professional quality version of the Ernie Ball Power Peg, which is a dedicated powered peg winder, but unfortunately it's only for home use (until you modify it). My hands are getting old, so if someone can make an appropriate tool that helps me restring guitars, I'm in!