Question about Peavey Delta Blues.

O.K., I have been missing out for a long time now. I just played a tube amp for the first time today..........now it is sitting in my living room! The clarity and tone from this amp is unreal! Plus, i only payed 350 bucks for this bad boy.

But the thing that impressed me the most, was the power. LOUD LOUD LOUD!!!!

This brings me to my question, this amp is only 30 watts, but blows my Marshall solid state 50 watt out the window. Why? I would even go as far as to say it is just as loud as a the MG100DGX Marshall too.

Anybody answer this for me? Why this lower wattage tube amp is louder then more powerful solid states?