The problem is that Ep.5 was such a good one that everything pales in comparison. It was a progression checkpoint update that gave intimate time with each of the LI one after the other. Of course any normal story update is going to suffer comparatively and feel like a step backwards.
That said, I will agree that it certainly felt shorter given how long was spent on it.
The name Mia originated from Maria, which is derived from the Hebrew name Miryam. Before its use was popularised in the US as a proper name, it was a nickname for, you guessed it, Maria. The most famous Mia is undoubtedly "Mia Farrow". Her real name was Maria Farrow. It's also popular in Scandinavian countries to abbreviate Maria as Mia. Maria Maria Mia.