I think training is definitely a great route to go with autos from what I've witnessed and read on here. My ONLY complaint about ponytailing is the fact that the girls get very bushy. I grew my two Auto Ultimates side by side and the girl who I LST'd at the beginning of stretch is getting better light penetration and packing on more weight than the girl I ponytailed. Now, this is not a definitive test by any means, just an observation. I haven't had to defoliate the girl I LST'd, and the ponytailed girl has needed a few heavy rounds of defoliation. Like I said, definitely not definitive. I could have two different phenotypes for all that I know.
Regardless, A+ growing here A-Train.