I dunno why, it just struck me last night, watching ENT on SciFi. Sort of an extension of the old saw with TNG season finales, where the setup was always more promising than the resolution. Not that I didn't enjoy the conclusions to the S4 story arcs, mind you, but the writing just seemed a little tighter in the beginning of, say: the Vulcan arc, the Augments arc, and the Romulan Drone arc.
Just my impression.
Just my impression.