I run a 350 diablo in a 2 x 4. Great light, top quality control during manufacturing and lifetime aftersales service. I sleep easy knowing the place wont burn down. The heatsinks and the Inventronics drivers are amazing, only ever get luke warm.
The only issue is the design of the board requires at least 18 inches head room, otherwise the middle is a bit of a dead spot. If you have the head room then its great for a 2 x 4. Johnny Holmes type penetration.
Saying all that I'd be open to a Mars light in here when the diablo shits itself. The gaps narrowed considerably.