>Logical n-Tier, deployed on one physical tier, leaves you much better positioned for flexibility.

Like John said, not every project demands that flexibility. Besides 2 years down the road any flexible n-Tier app won't mean squat when its time to scale ite, simply because the code you wrote back then will be a joke compared to the avialable.. and uncompatiable.. technologies and methods of tomarrow. Keep that in mind when you suggest what is mandatory in each project.