It worked for me but in lame mode. I used a cheap converter to change the voltage from 220 volts to 110 but the UK 50 Hz frequency made it work in two modes - fast and slow. The variable speed control simply did not work.
I think the US Vitamix needs both 110 volts and 60 Hz. to work properly.
I brought the US Vitamix back to the states, where it has worked fine ever since, so no permanent damage done by the UK electrical system. However, the TSA kindly unpacked my luggage when I first brought it to the UK, did not replace it properly and the chassis got cracked during the trip. I thought about filing a claim (two year deadline), but since the damage was minimal, figured that I would be unable to get a new one.
I have since purchased a UK Vitamix and have enjoyed smooth performance ever since.
A side note is that the US pitcher developed a leak. Not sure if it was a simple defect or UK water but I was stuck with that because I could not return it to US Vitamix for a replacement until I went back to the US. Actually, US Vitamix never asked for the defective pitcher, and just shipped a replacement to a US address.