We recently brought on a couple of PM consultants who are deep into Agile as a methodology, and decided to give it a go -- it's been about six months now and productivity has basically ground to a halt as we spend more and more meeting time endlessly sorting tasks into different little arbitrary piles instead of actually making forward progress. It's made communication with the non-software part of the company much more difficult, because they keep getting hung up on the jargon; we have to slice up tasks arbitrarily to get them to fit into "sprints," which go out of date minutes after the morning standup when the first non-planned bug report lands. Sizing is frequently an exercise in post-facto book-cooking: 'How long will that bug take to fix?' is like asking 'How long is it going to take to answer 23 across in next Sunday's crossword puzzle?' It might be fifteen seconds, it might take all day; until I have a chance to look at the puzzle I'm just pulling numbers out of my ass. The short timeframes encourage everyone to twiddle around the edges of things instead of doing real feature development; the arbitrary milestones serve mostly to make everyone feel like they're constantly falling behind.
I've discussed this with a bunch of people. Everyone seems to agree that we're doing Agile wrong, but even the strongest proponents of the methodology seem to be in complete disagreement on what the "right" way to do it is, or how that would be an improvement over the way we were doing things before.
So yeah. Not a fan.