Right on, Greg B and Tootler. It's difficult to give any credulity to the assertion that a half-step change in key would make a meaningful difference in one's ability to vocally "reach" the notes of a song.

Furthermore, the argument that F# is an easier key than G in which to play anything ~ on the guitar ~ is even harder to swallow.

The only way I'd even attempt to play my guitar in F# ~ especially to "jam" or play unfamiliar material in an improvisational situation ~ would be to capo at the second fret and play in E. (Key of F is tough enough; F#? Fuggeddabouttit!!!)

I'd prefer to play in the key of G, if I could only capo down a half-step, but I haven't yet perfected that technique...