IMO 10 years ago, ARB were leaps and bounds in front of all other manufacturers. Not even worth considering others.
5 years ago, definately still better than the rest but the gap had narrowed considerably. Still worth paying the bit extra for a premium product..
These days, no better than the others but with a price tag that always seems to be on the high end.
I had always been ARB through and through, but these days I seem to be buying less & less ARB gear, simply because its not the best anymore.