To the OP: Why not try it? Play it week to week and move around to different areas of the 'valley' and if you don't like it, move somewhere else. That's why you have wheels. There are plenty of other places nearby that are altogether different than the 'valley', such as Rockport, Galveston, Corpus Christi, Aransas Pass. Brownsville is not the ideal place to stay.
As the winter weather improves move up to the 'Hill Country' north of San Antonio. It's cooler there in winter but many folks like it. Tour around. What one person likes or dislikes shouldn't have any bearing on you. Good luck and safe travels.