I've got a 5150 combo and love it! It's cleans are much better than the head version. They can be nice and clean or you can make them nice and gritty. Plus, between the crunch setting on the clean channel and the lead channel, you've got everything from light crunch to face melting metal gain. It's quite a versatile amp in my opinion. I've never played or heard the Diablo, but have heard some good things about it. It would probably be a bit easier to transport than the 5150 combo. The 5150 weighs close to 90 pounds! If at all possible, play them side by side.