Hey tornado, how is the WM10 working out for you?

Warning: Mental Turbulence Ahead
I'm trying to decide between the compactness of the WM10 and the extra headroom of the WM12. Seems like they're close enough in price these days where those are pretty much the decision factors. I seem to be seeing ~$200 for the 10 and ~$225-$250 for the 12, each shipped, on the evilbay.
My current rig for all use is an Ashdown ABM500 II with a Berg HT210/115 stack. For what it's worth, I have a Baggs DI that I use for an upright bass preamp into the head's line input.
Gonna be playing both upright & 5-string electric, at low to medium levels. By medium I mean no drummer, that is, a washboard at most.

One band is cello/mandolin/ukulele/bass, there's some dinner jazz stuff (combos with moderate drummers), some jug band (hence the washboard), a piano/bass duo, and the largest band is an 8-piece funk cover band with a rock-bred drummer.
Now, I know the WM10 wouldn't be able to keep up with the funk band's rehearsal volume. But the 12....probably so, I'm thinking. The 1x15 half-stack coasts through in second gear. I would expect the 10, however, to pull off the rest, with the exception, maybe, of the biggest of the jazz combos (2horns/piano/guitar/drums).
So, I already have a modular, configurable big rig. Therefore expecting the WM to cover every gig is not a factor. The next smallest setup to travel would be the fairly compact half-stack, so maximo headroom in the combo is not really the issue, except as affects tone. (-->WM10)
I think the 12" in the WM12 might be nicer for upright. (-->WM12)
The WM10 is 100w @ 4ohms, the WM12 is 160w at the same. The 60w advantage would increase the WM12's value, as it would be a more viable backup head on the gig. (-->WM12)
On the other hand, for such a purpose perhaps the smaller box of the WM10 (less stuff in the Volvo) would be more convenient for such a purpose, if indeed it could serve the purpose (understanding that 100w of Workingman's is no substitute for ~400w of ABM, but this would be a make-it-through the gig situation). (-->WM10)
But then again, is the WM12 that much bigger, really? Likely not. (-->WM12)
Or, is it just enough larger to make owning it sorta redundant against having the compact 1x15 half-stack? That last is a major feeling I'm wrestling with. (--->WM10)
You can see my quandry. Fish or cut bait.
I understand enough physics to know what not to reasonably expect from a small cab, and I know either of these boxes would fit my primary intended use (ultimately, as an affordable one-hand rehearsal amp with good tone) excellently. ..I just don't have them available to A/B size and sound.
So..any counter-ramblings of your thoughts about what you might do would be most well-received.

Thanks, cheers!
- Rereading before posting...I think that practically, I'm leaning toward the 12. The 10 is just so damn sneaky-looking though!