I’m not sure how they compare between each other (Gabi and Hario), but I don’t really see much difference from manually pooring. Basically going the immersion route makes your water touch the coffee longer. That might extract more fats and make it less healthy, and in my opinion not a better taste (I don’t like other immersion products either). Taste is personal of course.
It might give you a slight improvement in comfort, but at what cost.
I was about to reply with ‘i guess you will end up using spreadsheets’, until this comment loaded.
I’m actually working on software to do this, with metrics, but it’s far from ready for primetime. So this is not helping (only myself to see that there is interest 😏).