As a Brit I think there's perhaps a cultural difference at play here. Most posters on this thread seem to be from the US and my perception of Americans (please correct me if I'm wrong) is that with a job holiday allowances are limited, not always taken, and when they are effort is made to deal with e-mail and the like during the holiday.

In the UK it's generally different. Allowances are more generous, generally taken and (perhaps most importantly) a holiday is pretty much a complete break from work.

The US system seems drive the wealth creation side of things forward, the UK (and much of the rest of the world) the quality of life side of things forward - with the 'best' option really depending on where you are from as much as anything.

I'm pretty sure your UK client didn't refer to it being a 'vacation' though!