I suspect the answer to this question changes as the architectural quality of a course improves, and most great courses likely don't have to make this choice, but which makes you happier?
One of the courses I regularly play had struggled with fairway conditions for years, losing the bentgrass/poa fairways almost annually. A couple years ago they brought in a new superintendent that vastly improved the greens almost immediately, and has improved fairways as well. Part of the improvement comes from the fact he took several of the generous fairways that where 50 yards wide in places, and tightened them by 10 - 15 paces in areas of width, allowing his chemical budget to provide the care they need.
It's clear the membership is ecstatic with the playing conditions and is more than willing to trade some of the architectural integrity (as width was used in angles of approach as well) for vastly improved conditions. If I'm being honest, while I miss a few of the areas that have been sacrificed, and don't particularly like the straight fairway mowing patterns, I do leave the course happier playing on improved conditions than I did when the architectural integrity was maintained, but conditions were not.
Which would you prefer, and can you think of other examples of this trade-off. I guess the obvious example is green speeds vs. contours.