Depends entirely on how many APs you have, what traits you plan on taking, and what weapons you plan on using. Basically, if you are are in a position where the one point deduction will give you another shot per round with your weapon of choice, then go for it. Personally, I love taking Fast Shot and 10 AG, and then firing two bursts per round in order to fill areas with hot, leaded death. If you have 8 or 9 APs, then fast shot is also a good choice because that gives you two single shots per round instead of one. If you have an AG of 7 or below, it's less worthwhile, except maybe for melee characters (who, unfortunately, might need the extra criticals from called shots for those times when they're "between" weapon plateus). While some weapons like the turbo plasma rifle might have a low enough natural AP cost to give you more shots per round, these are only available late in the game.
Keep in mind that sniping, while powerful in the midgame is useless in the early game (when you aren't skilled enough to use it) and not necessarily the best way to go in the late game (when you have access to powerhouse weaponry). Plus, as a personal choice, I prefer the reliability of a close ranged burst to gambling that an eye shot will cause a critical. Most combats take place at close enough range that a couple levels of bonus move should allow you to maneuver for a killing burst (or possibly two) every round. Of course, ammo consumption is an issue, but not a very big one if, like me, you tend to avoid extraneous combat. A bigger issue is collateral damage, but it's one I tend to just suck up and deal with. If Ian doesn't like eating my bursts, he can damn well stop drawing his knife and advancing to melee range every time he doesn't feel like reloading his weapon.
