I don't know too much. However, I know that with masonry walls, they are non-load bearing walls. That means columns and beams will need to be bigger. Brick walls could have more problems with cracking and workmanship issues. Sound isolation could be not as good. Of course, non-load bearing walls can be removed if you want to modify the room layout. In Hong Kong, there is a restrict regulation for the quality of concrete. However, I am not so sure about quality control of bricks.

Just to share some experiences from Hong Kong. Faraday cage is surprising not so much an issue for mobile phones in HK buildings. The rebar can help shield mobile frequencies; however, depending whether granite is used in the concrete in Malaysia, the concrete can give out a radioactive gas called "radon gas"  . We have this problem in all condos in HK as our concrete has high granite contents.