If I go Sith Inq, you're nearly forcing me to go Artifice, as Inq's top crew crit is Artifice Crit +5.
Source? From every companion list I've seen, there is no Artifice Crit bonus on any of the standard companions, in either faction. Best crit on the Inquisitor is +5 to Archaeology crit, by Talos Drellik. As a matter of fact, the Inquisitor does not get a companion with a crit bonus in any crafting skill at all. All crit bonuses for that class are in gathering and mission skills.
is one of the better full lists out there.
has a nice tabulated section of crew skill bonuses that is easy to see at a glance what each class' best crew skills are.
From previous MMO experience, I would lean toward saying that any crit bonus is likely better than any efficiency bonus by several orders of magnitude.