My everyday brush is a basic one with brass bristles from Libman. I wanted one brush that could work on any grill grate including cast iron. My research indicated that a steel wire brush might be too stiff for CI and I didn't want to hurt any that have a porcelain enamel coating. And also, every steel wire brush I've had lasts maybe a season, as the bristles just wear away or get bent.
This one, despite brass being softer, has held up BETTER:
http://libman.com/products/69/ This long-handled version will be next; I didn't know about it until just now:
http://libman.com/products/12/ I have a version of that brush with plastic bristles for help cleaning out grills/smokers. Love the large hook on the end and contour.
One caveat with these Libmans (and, I suspect, any that similarly are made of plastic). You must limit your time using the metal scraper on a hot grill or the metal scraper will fall out of the handle as the plastic surrounding it heats up. That happened, I let everything cool off and reinserted the metal scraper, which hasn't fallen out since!