After a week pondering and discussing the merits of each once again, with anyone who would listen, this morning I finally placed the order for my trailer. In the end I went with the BOB Yak.
Whilst it really was pretty much a toss-up between that and the Burley Nomad, I just feel that the BOB Yak gives me a little more flexibility even though the load capacity is slightly less.
The Nomad holds 45kg but I think my tendency would have been to load it to capacity just because I could. The major plus point being that I could then dispense with all my panniers and racks. But as people have pointed out, it would be handy to retain them just to hold food, rain gear and items I needed to get to fast. Having then chosen to keep them, I decided upon the Yak because although the load capacity is slightly less (32kg), it would allow me to cycle easier off-road if I ever had to or wanted to. It is also less wide than the Nomad and offers me more peace of mind when it comes to cycling on narrower roads or through towns and cities and along busy roads. Also this week, I tried riding with a single-wheeled trailer for the first time and liked the way it handled.
The trailer is being delivered to the UK and I will collect it on my way back across England en route to Dover :)