[avar]

Its highly subjective but I prefer machines, tried a peg-head but even though changing strings and initial tune-up was easy I hated being unable to fine-tune the strings ... they were always a little off.
Machine heads are easy and the quality ones (like Sloanes or Fustero) are very light.

[BrianBurns]

Hello Avar,

Planetary Pegs are actually fine tuning machine heads that look exactly like ebony pegs. The 7mm guitar pegs (#745A) weigh only 10 grams more than a set of ebony pegs. Even allowing for the wood that is removed from the head when installing conventional machine heads, there is a really noticeable difference in the balance of the guitar.

Also, less weight on the head makes for a faster attack and shorter decay of the note i.e. a more "flamenco" sound.

A friend of mine made a video clip of me demonstrating flamenco vs classical guitar types. He liked it well enough that he posted it on his youtube account. I use high quality Sloan tuners on my classicals. You can see, and hear the difference here:

http://www.youtube.com/watch?v=kLzSYXlLBnI

Cheers,

Brian