There were two things that really helped this time:
1. Internet Access.
Frankly, the days of mocking people for 'needing' internet access on holiday are long gone. When you run a one-man 24x7 business accessible from every country in the world with an IP address, yeah, it does help to be online occasionally. I've found that knowing that there will be reliable net access in the evenings has allowed me to completely relax during the days and really invest that time in the kids, rather than trying to get rid of them for an hour or two during the day to get email done.
2. Seven Days
In the past, we had often taken five day breaks rather than seven. The psychological difference between a five day break - which really means just three full days off - and seven is remarkable. I hope to take even longer breaks in the future.
My only disquiet about this holiday has been the cost. At a trivial count, we've spent at least £1500 and probably closer to £2000. I just feel that's really very expensive for what this trip was. The accommodation was great, but the eating out and the activities we did during the days were a lot of money for pretty average stuff.