I never saw the Michael Ironside episodes of SEAQUEST, just the Roy Scheider ones. If anyone saw both, whom was better?
As ThunderAero points out, the show changed when the captains changed, when much of this thread has shows who were trying to maintain their formula with different casts.
Under Scheider, it was primarily a sea exploration/sci-fi show. Ironside's run, explicitly stated in his first episode, was to be much more military driven, and only a couple sci-fi episodes at best.
But it's interesting that, whenever Scheider came back (and had to because of contract obligations), the writers tended to beat him up to holy hell -- probably some lingering bitterness between the two camps. Scheider made 3 appearances: one to transition the captaincy to Ironside, the second as a rival to Lucas and the crew (and Scheider had to eat crow at the end of the episode), and the third which had him inexplicably and uncharacteristically in a black ops mission, which revealed that he had a hand in some really dark genetic engineering.
I've no doubt that Scheider and Ironside got long relatively well together on the show, and the rest of the crew thought of him as a father figure, but that the producers and writers just had it out for Scheider.
On a side note, I felt Ironside got a bum deal out of all this. In hindsight (thanks to Netflix), he's someone the crew isn't accustomed to, but it's a new world and he's no nonsense. Some fans in the 90s blamed him as one of the reasons the show failed, but I thought he did okay under the circumstances. He never got to lead a TV show ever again. Rather, the meddling network execs, the producers who were too happy to comply with them, and the departure of Spielberg (who could have reined all that in), plus that horrendous new intro theme, is what killed the show.