The rule of thumb is for now - if you have to ask, it's not stable (or fast) enough. On a side note, there are no OTAs in the sense most people use them - packages do get updated more-or-less continuously, but that is not a set of tested firmware upgrades (in other words, nobody cares if a snapshot from day X can be upgraded to snapshot from day Y, that level of validation will only be reserved for full release upgrades, if at all).