I have to say, to release Lab Coat in the same expansion as Research Notes, Gray's Anatomy, and Grim Memoir is a cruel joke. Clearly Lab Coat is better at serving cards from older expansions, but that's penalizing players getting into Arkham Horror LCG starting at Scarlet Keys.
Anyway, here are the 21 cards that Lab Coat makes a difference on (19 if you don't count the non-recommended options):
Now, the positive effect that Lab Coat has on most of these card amounts to a +1 boost, which given that it affects neither basic actions nor non- cards, is just inferior to a simple +1 boost. The truly unique to Lab Coat benefit is the ability to succeed tests on an draw. However, this requires your test to be difficulty 1 (or less), which at which point that extra protection is mostly for peace of mind; at best your Lab Coat protects you against a 1 in 14 chance.
In conclusion... I don't ever want to consign a card to binder fodder, but man is this card trying it's absolute best to be worthless. It's useless by itself (unless you count soak but once used as soak, it cannot be used for it intended purpose), and when in a combo, either the test is too trivial to warrant its use, or too high to make it anything other that a worse +1 . It should've cost 0. I like that now has a body slot asset, and a flavorful one too, but the card pool does not exist to make taking it worthwhile.