Wide Awake, although I have done sessions in 'Pro' studios I haven't actually worked full time in one. I apprenticed in a small 'Semi - Pro' studio for a couple years doing some bands but mainly Jingles and Voice over type stuff, and now I do mainly live sound.
I am only now putting together my own PC based recording rig.
The above lists all the acoustics I have had the opportunity to record, I haven't done a 'real' acoustic player, mainly rock guys who wanted acoustic for a ballad or to fill out a mix.
So while you are probably right about the Taylors, Martins and Gibsons being the most common, I haven't come across them.
I have only recorded maybe a dozen different acoustics and about 4 were Yamahas, plus the studio owned a Yamaha and a Takamine (sp?).