Yeah the tubes can be hit and miss. I actually have a bunch (30 or so) of EF86 on hand that I've been meaning to go through and test for microphonics and get rid of the really bad ones. I think it's fair to say that all EF86 are microphonic, maybe 50% or so are reasonable enough that in most applications you won't notice, 30% are bad enough to be noticeable, and 20% are so bad they're unusable.
These are numbers I pulled out of nowhere and are not measured statistics, but you get the idea. In my anecdotal experience JJ/Tesla have been consistently low microphonic, TAD have been hit or miss, and winged C (Svetlana) have been hit, miss, or really bad miss.