Found myself at BD today, albeit not for as long as I would have liked, and had a brief chance to try out the Mesa WD-800 through a couple of VK 112s. It's a pretty capable amp - I particularly liked being able to boost the bass whilst engaging the HPF. You could really see / hear / feel the HPF doing it's thing with significant cut when set at 125hz but much more marginal when engaged at 25hz. The combination of amp and cabs was crisp and articulate.
I would need to spend a bit more time with it before having something more in depth to report but first impressions were good and I suspect more time would only confirm that view!
Interestingly Mark was gobsmacked when I pointed out that these are available at $999 retail in the US. He messaged Westside whilst I was there to find out why he can buy more cheaply from a US distributor than he can from them!
Like us, he would have expected these to be priced to allow a £999 retail price in the UK allowing for VAT, Customs and transport.