Andromeda fell way harder, way faster. Once Robert Hewitt Wolfe was out the door it was practically unwatchable, save for a few minor exceptions.
The exceptions were pretty major. The post-RHW episodes in seasons 2-3 that were written by Zack Stentz & Ashley Edward Miller were consistently almost as good as the first season and a half had been. In fact, season 3 was bizarrely schizophrenic, because Stentz & Miller were still essentially writing the original incarnation of the series while the rest of the staff were writing a new, dumber, more fanciful version of the show.