To give you some idea as to how much attention to detail The Alkabor Project goes into, see
http://www.eqemulator.org/forums/showthread.php?t=40543 for a good example.
Project EQ's data isn't as accurate as TAKP's, but they are improving largely because they begun importing our work. (actually several TAKP devs are also PEQ devs)
Stock EQEmu isn't as concerned with gameplay mechanics accuracy as TAKP is, so many of the finer details are incorrect using their builds. They are more concerned with getting clients working and mobs pathing and such and they have a much larger subset of features they need to support. However EQEmu mechanics are also improving from collaboration with TAKP and we share discoveries often.
TAKP has the most accurate mechanics of any emu in large part because our users played EQ stuck in PoP for 10 years so the Mac users know all the quirks extremely well. It's not some 15 year old memory for them as their server shut down less than 3 years ago and have been giving us feedback since. They also provided me with a mountain of logs.