Hi Colin
We drove from Hook of Holland last year and we did find the conditions slightly different to driving in France. We unfortunately docked at rush hour so met more traffic than in France. However, the main difference is the bicyles. In many places they have right of way and their own lanes, which does mean that there is more to be aware of. Also the language is TOTALLY different and the signs make no sense whatsoever. This is different in France as very often a memory of school-boy French kicks in. I would suggest you get a copy of Caravan Europe 2 from the Caravan Club and on page 497 there are some road signs and markings together with cycle signs. I think if you could get familiar with some of these you would feel more confident.
I realise this sounds a little worrying but it is not meant to be. I just think for your own peace of mind a little knowledge would make for a more relaxing and enjoyable time. The country generally is very prestty and the people like the British so you will have a good time. If I can help with anything else please ask.