Enhanced should work for most printing projects. The Photo setting would best be used for photographs and brochures.
The enhanced is also used for when you want more accurate colors to be used- ie. if you specified a certain cmyk formula. If you go to the menu on the printer and select Information/Sample Pages/cmyk sampler pages, this will print up a multi-page chart of color formulas.
I don't know what kind of printing you do, but if you needed to print an exact color (maybe matching your company logo?), you would want to go by this chart and use the Enhanced setting and the TekColor Automatic settings. The other settings may come close, but not precisely.
As for the ink used, yep, plenty more is used in the Photo setting.
Nick