I have played Sabre River and enjoyed it very much. It too depends on having a good DM, but I don't think its nearly as demanding of a module as CM1 and in particular I think you can run CM3 'out of the box' without alot of prep time and additions. Sure, it probably would help to expand the dungeons to make them less linear, if the PC's were into dungeon crawling, or to flesh out the setting if the PC's are in to RPing, but none of that is strictly necessary. In fact, CM3 is a great example of the sort of event that might play out within a campaign using the CM1 framework. As far as I know, that is precisely what all or most of the companion modules that follow CM1 are intended to be - on going events within the two or three year long 'Test of the Warlords' campaign.