Not sure if anyone is still curious about this thread, but I thought I'd update.
I took delivery of my Ultra this evening! I only had a bit of time before the wife went to bed to play with it, so I've only tried the Woods with my Patterson Audio 1x10 cab. This is a custom built one-off cab, so me reviewing the sound of the combination is probably of very limited use to anyone else.
However, I can say that the Patterson cab is quite a punchy box, similar to the Eden 112XLT (which I compared it to on a gig). The Patterson has a smoother high end due to the coax tweeter, but the combination with the WW still sounded clear and bright to me - exactly how I like it.
So far, I don't hear any inherent 'thinness' in the sound of the Walter amp (although supposedly this is more apparent on a gig than at home). The WW is definitely very articulate, but I was able to get a lot of mileage out of the EQ to get the sound I was looking for with my little Patterson cab. This seems to bode well for the Woods being fairly compatible with other cabs if you're willing to tweak the EQ a bit.
Tomorrow I'll get a chance to try the WW with my AE410 and I'll post some comments. I'll try not to write too much, since I'm still on my 'honeymoon' period with the Woods and I'll only be doing a 'bedroom' test anyway. After my weekend gigs, I may have more to report. I'm hanging on to my Markbass SA450 for now to do some direct comparisons, so maybe that will be of some help since a lot of people are familiar with the Markbass tone and how those amps react to certain cabs.
Here's a picture of Walter and Pat: