Not much better than using the iPhones VIP list to control notifications to watch (in my case, Pebble).
No evidence of dynamic learning, or anything more than pattern matching on senders, subjects.
Pebble watch app has no ability to actually manage email - can dismiss eNotification, but still must go and handle email. You end up having to touch email 3 places: watch, the eNotify app, and the actual mail app. Maybe four, with phone notifications.
Perhaps worth it if you are on call, need to respond ASAP to email from certain customers. Not worth it to me, as a way of handling email overload.
Would be more useful if it could handle text messages.
Drains battery, both on iPhone and on Pebble watch.
Overall: dont waste your money.