FWIW, almost everyone I know (men anyway) who have a Glock 26 or 27 wind up putting an extender of one type or another on 'em if they want a place for the pinkie. With the popular +2s, I think it actually makes 'em longer and bulkier than the Model 29 with the Pearce +0 (which is just right in my hand - and no "excess" in holster).
Per http://glockmeister.com/gpistols.shtml, compared to the 27, the 29 is roughly just 1/2" longer, 1/3" taller and 1/10" wider. But 2.7 ounces heavier. :(
Well Bubba, I was wrong on the length. Got pictures processed and the thing looks closer to 66". Hope that doen't make the knees start shakin' again.