we had the pleasure to be guests in Olga's and Jose's place for about a week this summer and I enjoyed every single meal I had there. There are plenty of good restaurents in Trinidad, just usually they get kind a boring after one day coz eventhough they have severly dishes on the menue - most usually taste the same.
Not so in Casa Villalba - the menue is small, but u don't find two dishes that even come close to each other. The Paella is excelent, the lobster smells like heaven - but my favourites were the Pollo Escambray and the Gazpacho. if you spent enough time in cuba and get sick of rice and beans - you'll undertand me - give it a try.
if you don't happen to be around for dinner or just feel like a small bite - they offer breakfast and sandwiches as well - all for good value of money.
some people here complained that the waitors are no good at English - while this might be true in the end this is Cuba & people speak Spanish here, not everybody is an expert in foreign languages. Olga and Jose do speak a little English though and it is usually enough for you to order food and drinks.
If on the other hand you make the effort and try a little Spanish - you might soon end up in a chat about their life back in Spain and how they ended up in Cuba taking over this restaurant.