I just bought one today from the Netherlands at $35. Let's see how it holds up.
I do not have any games yet that really take advantage of six-button-controllers, but this might change soon.
Got the controller in the mail today.
As mentioned somewhere else in this forum recently, we euro cavemen prefer to ship our used videogame stuff as filthy as possible. This controller was no exception, since the whole pad was sticky as well as the cord, which also had stains on it.
So I followed the usual procedure of disassembly and cleaning all plastic parts in a bowl of water and dishwashing liquid, cleaning the cord with water and germicide, and the rubber membranes as well, sparing the contacts.
Now that the controller is reassembled, it feels pretty much like the original SNES controller in my hands. The buttons and the d-pad have next to no difference in visual appearance and pressure sensitivity. As mentioned by Sadler, my digit fingers are automatically searching for shoulder buttons which don't exist of course.
To me, this is a very nice 6-button-controller.