I owned a 212 V30 RL, and compared it to some different 212 Cabs.
Basically one can say, it is a very useful Cab! But in some way it was too "wide sounding" for my personal taste, so i switched back to a Mesa 212 Recto H. But that´s a different story.
I compare the Diezel with a Bogner 212 Oversized. Both had a great and nearly 412ish-omph! But the Diezel is more tight and much faster-responding. The bottom end is more controlable, the Bogner always seem to be a way "compressed"!
Compared to the Mesa, which is a lot more straight in your face and a bit spiky, the Diezel is much more huge and non-directional.
It´s a bit difficult, when playing alone, the Diezel is far the best 212 cab I´ve played, but in my Band the Mesa won!