Re: Why did Satch choose 6105?
6105's are tall like the 6100's, however not as wide, the main advantage, the intonation is better with 6105's. They are easier to hold true in the beginning and especially over time as the frets wear, 6100's are so wide, they wear uneven causing pitch fluctuations all up the board according to the different amounts of wear at different areas. (Wider frets have more of a top area to wear unevenly)
However it's also about feel & tone, 6100's do create a little different tension when fretting due to the contact points of the string to the fret and measurement between the edge of each fret surrounding the area being fretted. Tone, well of course there is more metal involved (Contact with the string) with 6100's, so the tone is slightly effected when compared to 6105's.
Depending on ones playing style, there are pros and cons to both.