Hi Southeast 30
Timber floor construction.Easier to make future changes regarding utilities layout. Concrete floors require shuttering, rebar or mats, etc,etc. Hence additional costs. The loading on the walls is greater. No problem because on a new build this will be taken into account. But again future changes to the house eg, a wider opening in an external wall to accomodate a conservatory would be more expensive. As opposed to a conventional floor because the loading would be diiferent requiering a different approach/materials. I like to always be able to allow for future alterations in a home.
If your concirn is noise then a product is available from Dupont specially designed for this purpose. It can be used with solid timber floors, floated laminates and carpet.
Cost would be a consideration as I am sure that concrete suspended floors are more expensive. The saving accrued by using conventional floors could be put into other areas of the house.
Concrete is a very good medium in compression, but not in shear or tension, hence the use of rebar. But just the thought of chasing for wiring gives me the creeps. All it needs is a little movement and you're asking for a crack to develop over time. I know that in a normal house the span of the floor is not that great and therefore the pressures are less, but still.....Maybe I am just old fashioned and must wake up to the times.
Personally I would go for timber.