Season 2 shows a noticeable shift in both the plot of the show and the characters, surprising as it’s so early in the show’s run. From the first episode of the new season Atlantis has regained contact with earth and obtained the marvellous plot device of a space ship with a transporter which is immediately put into use to save the day whenever necessary. I wish they’d actually been out of contact with Earth for longer, to establish both the base and the show as distinct entities. The ability to get help gave the writers the opportunity to become a little lazy at times and the show suffers for it.
The character changes are also a bit strange so early on. While Ford had suffered from poor character development in the first season it seemed a strange choice to just give up on him and start afresh. That said Ronan (and to a certain extent the recurring Major Lorne) made interesting additions, forming relationships a with the other leads a lot faster. Colonel Caldwell also helped to bolster both Weir and Shepherd’s characters by giving them someone to play against. Meanwhile making Dr Beckett a regular was certainly well deserved. Of the returning cast a lot more focus seemed to be placed on relationships, both the developing of them and the occasional breaking, a very important element that SG1 didn’t always manage to protray – I think the Atlantis characters have probably developed more in 2 seasons than the SG1 team did in 6.
The plots themselves are generally pretty standard sf fair that’s been told in half a dozen star trek and sg1 shows before to be honest. Some are re-jigged well (e.g. Coup d’Etat and Inferno) and some just get rather sloppy (Epiphany and Trinity for example). But frankly I don’t watch the show for innovative plots, I watch it ‘cos it’s fun and the dialogue makes me laugh. It’s got twice as much life in it as SG1 does these days and even poor episodes manage to make me laugh.