I really didn't care for the season one set, although, I think that one was more authentic to the movie starring Jack Lemon and Walter Matheau.

I liked it! I've only seen the first disc, though, but so far it's great! The episode introductions by Gary Marshall, the comentary by him and Jerry Belson on the pilot, the comentary by the actress who played Gwendolyn Pigeon-I forget her name, the ABC promo, and the clip of Tony Ranndall on "THE MIKE DOUGLAS SHOW".
Unfortunately though Netflix doesn't have the last disc with all the extras for some reason, so it looks like the only way I'll get to see them is to buy the set.