
I completely agree with the other review, but I feel like it's worth mentioning that this card synergizes really well with Ursula Downs' ability. Both Fieldwork and said ability require you to move before you can activate them so you end up investigating after moving very often. It gets even more efficient once Pathfinder enters the mix. Almost every Ursula decklist on ArkhamDB includes this card. It's almost like a secondary signature card.
EDIT: as a side note on Fieldwork with Ursula, if you have Jake Williams in play, you can make a move action without taking an AoO. This means that you could move with an enemy engaged, use Fieldwork to evade that enemy, then move away (using your extra action to investigate if there's a clue left on that location) so that you can avoid becoming engaged again during the enemy phase. I hadn't thought of this before because I almost never actually play Jake. Becomes more efficient with Pathfinder, of course (though you can't activate Pathfinder if you have an enemy engaged iirc).
It also probably works well for Luke Robinson, though probably not to the same degree. You could use Dream-Gate to warp across a scenario and then use Fieldwork to investigate the new location. This also improves with Pathfinder, of course. That being said, I doubt that it is an auto-include in a Luke deck, as he can't necessarily Gate Box every turn, and he doesn't inherently get perks for movement.
Don't forget that it can also be used for non-investigation skill tests provided that you move to a location with at least one clue. In practice this is not terribly common. I have run into situations where I want to evade an enemy who's one location away to help a teammate. I have also used it for questing tests, though some of these need all of the clues gone before you can actually do them. Once again, Pathfinder helps a lot to make these acts more efficient.