I have always been a strong proponent of AEC (high contrasting color); however, we have switched most of our immunoperoxidase stains to DAB because of convenience.  We use DAB+ from DAKO and have been very pleased.  It is very easy to prepare (1 mL of substrate buffer + 1 drop of liquid DAB+ solution).  We apply the DAB+ to our tissue sections for 10 minutes.  It gives strong, uniform, and consistent staining. I still use AEC+ (also from DAKO) with certain infectious disease antibodies (where I need differentiate immunoreactivity from endogenous pigments), as well as with melanocytic lesions/tumors.

R. Cartun