I can't say every AM cylinder I've seen has been bad, there are some dandys out there though.
Some of the inconsistencies have been favourable as far as setting squish for me without machine work on my 066 the OEM was either 35 or a head slapper ,I mixed a few parts and got 25 not that its a feasible tactic running a business but a hobbyist it was fine.
In contrast an aftermarket 028 cylnder needs an obsessive amount of work just to run reasonably .
Some are better than others, but in life yous buys your ticket and gets your ride , and completely understand why anyone would not recommend a crap shoot . Broad generalization is just not something I like to do.