If you feel that the MUT is plain, then I'd say go for the Portofino. You'd be staring at it everyday and you wouldn't want to regret looking at it after 2 weeks of wearing it.
The ETA based movement is still a GOOD movement. Easy to service and parts are easily available.
Resale is poor for both. Consider looking for a used one.
I thought Portofino are no more ETA movement now?! Now is Selita movement rite?
To be honest, I'm not sure. Personally, I've yet to come across CONCRETE evidence that suggest it is either ETA or Sellita movement. IWC is tight lip about it.
In any case Sellita has been making parts for ETA movement and has its own version of 2892-A2 which is built from the same blueprint. Sellita has been supplying ETA with parts for many years.
If you're really particular about this, you may want to wait a little while more. IWC has already announced their own in-house caliber to replaced the current 30xxx caliber in all the entry level watches (portofino auto included).
But personally I won't hold my breath. It's good as it is already, be it ETA or Sellita.