Martin I think the reason you have had so few replies
is that without seeing the job it is impossible to give a reasoned reply.
There are so many aspects, it is impossible to say what is best for you, but then I would go for wood
although it would almost certainly cost more, but then I wouldn't if there was no underfloor ventilation but would if access was poor but then it's quicker to lay concrete but then you have to wait for it to dry.........