Slow walking speed, don't go for more than an hour or three. I always watch mine, and manually inject catches etc as I see things I want. Basically, I figure that if I baby sit the app and do most of the control manually, then if what the devs say is true, Niantic shouldn't be able to find me. That being said....we all know it's likely to get you banned if you do it. You shouldn't do it if you care about the account living forever.
Play for one full month with both, and make your own decision... I saw PokeNinja's bot, and the features look awesome, but at the same time, that's the kind of features that get you banned. Especially the gym stuff... And I'm guessing its some of those more aggressive/ban-able features that get that experience faster.