I used to have a Riff Raff, which in the end I decided was just too light in the bottom end for me. I currently have an Emerald and Black dog in different guitars, the Emerald is definitely hotter and more full than the RR, and has really smooth upper mids and highs - very well balanced. The BD is more low mid focused and slightly more open than the Emerald.
I think if you're looking for more output and thickness than the RR, but not as much bass/low mids as the BD, then Emerald would suit you. It does feel like a slightly less vintage pickup though, due to its higher output, so a mule might actually suit better if you still want that real vintage output/dynamics, etc (not that the Emerald is super high output or anything, it's just not quite as pure vintage in feel imho)