The ZCI should be a better motor, it's higher TPA. However contrasting that, some ZCI parts are terrible, most SHS parts are good. So it's really sort of a toss up, I think I'd trust the SHS further. But the ZCI should be a better motor from a technology standpoint lacking a better term. That said I've heard good from both, and either will have a good neo can, and you can always swap the insides from a high TPA armature into the SHS or ZCI at a later date making up something good if either gives you issues.
Luke