I've run this card a few times now in a Rex deck, and I have to say that it impresses more often than it disappoints.
I agree with an earlier reviewer that stated this card might as well read "You lose an action, another investigator gains an action" because that's effectively what this card does. But it also gives options.
I tend to play the dedicated clue sniffer on my team, and there are occasional rounds where another investigator (usually the combat monster) is trying to optimise a turn, but just needs one more action to pull it off. Or, for some reason, sniffing clues isn't needed for one particular turn, and Rex Murphy can't contribute what the team needs. This card can be used to shift one of your actions to an investigator who can put it to better use.
There's also the icon on the card, which can come in handy in the worst cases of scenarios... but at that point, you're probably in trouble.
I find that I tend to want five cards sitting in my hand anyway, to enable Higher Education, and the perfect candidates for those five are cards that are fine sitting in my hand until a situation occurs where they're exceptional. This, plus two copies of Delve Too Deep, gets me over half way there!
For a 0xp card, this one fits the bill.
(NOTE: The above review is based on Rex Murphy, in 2 or 3 player games, on Easy/Normal difficulty, YMMV.)