Chilling, thrilling, engaging, enthralling, intellectually stimulating (or as much as LiS would dare allow a viewer to be), this one is great stuff.
The usual LiS-oriented logic gaffes exist, but they aren't many (only one really) and the concept is so well used I'm more than determined to readily forgive it. (they DO mention the Robot being in the room despite having moved it half an hour prior to, but where is the original Dr Smith then? Not being chased by the future-era Smith, who's too busy eating quite the breakfast to be concerned...)
There is also a terrific revelation in this one, as to what would happen if Dr Smith never boarded the Jupiter II. This turning point may also be why the Robinson family keeps Dr Smith around in later stories when, by that time, even they might be tempted to jettison him into space for good.