Madrid - reservations required or recommended at these restaurants?

[spicygal]

Does anyone know if reservations are required (or recommended) at these places for dinner:

La Cabrera
Gabinoteca
Arzabal
Biotza

The website for La Cabrera is particularly confusing to me as I don't speak the language and I cannot tell if there are different locations for "Gastropub" versus "Casa de America" - they are different tabs on the site.

http://www.lecabrera.com/gastro.html

Thanks.

[erica]

You need to book Arzabal. That was my impression on a weeknight last January.

Be aware that there are two locations, a few steps from one another--the original and a relatively newer location. We had a very good dinner at the one NOT on the corner; I believe that they share a kitchen.