My I9 1/1 hubs have been solid for almost 2 years now with quite a bit of riding, and I live in the PNW so not necessarily dry conditions either. I've pulled the hub apart and popped seals on the accessible bearings once or twice. I do know that the 1/1 hubs come with cheaper Enduro bearings than the Hydra (abec-3 vs. abec-5, I believe), but I'm assuming the issues have more to do with Enduro's less-than-great seals rather than the abec rating.
More recently I've started popping seals on brand new bearings when I'm installing a given part just to make sure that they've used adequate (and high-quality) waterproof grease. Some bearings I've received have a pretty minimal grease fill, so it might be a question of Enduro's quality control in grease filling those things. I kind of think of it in the same way as Rockshox and Fox forks...sometimes you buy a new fork and it's built properly, other times it has virtually no grease or oil to be found...