Instead of takin' the slow train, I decided to take the bullet train from Oporto to Aveiro. It was expensive, but it was totally worth it. Got there in less than 35 minutes. For a trip that ussually takes an hour, it was awesome.
The seats were confortable, they serve food and drink, but I just wished they had plugs to charge batteries. It makes sense, since this train is meant to go all the way to Lisbon.