Mate of mine came round with a 5150 and a spanking new Zilla fatboy. We made lots of noise. Then moved cables and suff around and made more. Then did it again.
Proof of existance/reality.

Ubercab, stock loadout.
Orange - swamp thang and jensen C12k
Zilla - swamp thang and legend
CL100EQ
Powerball
6505+
JVM
Legras were the weapons of choice, since they're awesome, but the jacksons got a look in for the BK comparison, of course.
Findings - short version
Uber >>> Zilla >>>>> Orange
CL >>>>> . (for my tastes at least)
I shant bother with the in depth and subjective assessment of each, as we'll be here all day. I certainly wont bother telling you what quite common amps like 5150s and JVMs sound like (though if you have any specific questions regarding comparison between them, I'll be happy to answer). I have two main observations:
The zilla killed the orange, which surprised me...I mean, I was perfectly open to the possibility that it would be better/I would like it more, but the difference was really shocking, especially given the similarity of the loadout (to my ears at least; one could elaborate with various adjectives like 'clear' 'smooth' tight' 'full' blah blah). I didnt expect that, given that the orange is quite good and has a generally superb reputation. I even moved them to the same location in the room to make the comparison to make sure that couldnt sway anything. The Ubercab rules all, however, quite effortlessly. Though, the zilla has quite the 'ubercab lite' sound and feel; like a both physically and sonically stripped down and compacted ubercab; about as tight, the Ubers low end could easily engulf the zillas with a similar actual magnitude/balance of lows in the tone, but they have as similar depth, thickness and size as I can expect a 2x12 and 4x12 to have to one another, both have good note definition (but the ubers got more) both are quite smooth souding (but the ubers smoother) both are punchy, but the...blah blah you get the idea. That may sound like an uncharitable comparison, but it in fact means I love the zilla!
And
This is the first time I've had the chance to play multiple guitars through a 5150, and I was really surprised how homogeneous it made them all sound. Theres more difference between guitars by far through all the other amps there. I didnt expect that, for some reason.
Really, I expected to have 5150 gas today, being reminded what they sound like in person, playing one with my guitars and cab. I thought it might fill a hole between my amps that I could use to provide clients with a wider and more precisely realised range of tones (within the realms of metal at least)....but I'm not that fussed. I wouldnt say no, it'd be handy to have one around, and the 5150 has a 'classic modern metal' (oxymoron I know) sound is one that it would be nice to have (relatively) easy (easier/whatever) access to...but the zilla came out of left field, and impressed me enough that I kind of forgot about it :lol: