Simmed a 418 Sustaining Alchemist Stone on my Outlaw Rogue now and compared it with my 405 Hunger of the Pack. The difference was 0.024 % DPS. I would also argue that the extended phial duration is pretty meh as well, not to mention the fact that its inconsistency should warrant a further increase when compared to the HotP. Since Vers is my best seconday stat, I would imagine it doesn’t fare much better with other specs either, making me feel like a fool for having spent a Spark of Ingenuity on it early on.
Given the wide range of useful craftables for other profession classes, I would argue this item could well do with a buff of sorts.
On a second note, I wish there was a system where one could destroy items to get Spark of Ingenuity and spent Valor Points refunded. Not a big fan of having a system where mistakes are irreversible and just leave you lagging behind for several weeks. Granted, I should have done my homework in this particular case, but even so I would have liked to see that changed. Crafting items is quite pricey regardless, so I cannot really see it being exploited.