I think we lost the point a little on this thread... is there a difference between the Ping and the Gotoh. my answer.. depends on which ones you get. Gotoh does have a line of $13 machines, and they are just as good as ping, but in the long run, they will wear out.
The real problem is not short term, but long term. After a while, the Pings will become very stiff to turn, and the worm will not mesh properly with the gear. You will be able to see metal filings flaking off from both components. Even the cheaper gotohs will do this.
However, Gotoh produces a line of machines in the $30-$60 range which will easily last for at least 10 years and more with a bit of maintenance. They have enclosed gears, making the mesh between worm and gear more consistent.
I really prefer Gotoh over Schaller, even though they are in the same price category. Schallers tend to breakdown after 3 or 4 years. I have had several guitars fit with gotohs and they all stand up to years of daily use.
Maybe they use a better gauge of steel for the worm and gear... maybe they are better designed than Ping and Schaller... what ever it is, they are superior.
So, the Pings may be great right now, but they will eventually start to wear out sooner than other brands. A good quality Gotoh in the mid price range will do the trick.
For curiousity sake, I have the current machine heads on my guitar.
2 pairs of Sloans,
and 2 pairs of Gotoh (one set of mid range, about $30, and a set of the more expensive Rogers copies)
The Gotoh are my machine of choice simply because they work well and they are very cost effective. Sloan is a great choice for aesthetic, quality and price.