I have always used tiles/timber floors and always carpeted bedrooms. Never had problems leasing due to the location of the properties. To my surprise, i heard some people do prefer no carpet anywhere as kids are allergic to the dust that lives in the carpet. I would probably speak with the local property manager as they should have a pretty good feel of what your prospective tenants will like. As I mentioned, the location is probably more important. If you can get away with not spending extra money, then dont.
I would either go the split. Timber living areas and carpet bedrooms, or I would go fully timber. I would never go fully carpet. Especially not if your floor boards are good.
Carpet is cheap to replace, but needs to be cleaned whenever a tenant moves out (usually done by the tenant but not always). Floorboards cost nothing once they are reading and only need to be swept when a tenant moves out…super easy to maintain.
I agree with Toni….speak to your property manager and see what they think. But at the end of the day you are the investor…you make the decision based on your research and what you think will make the most profit. Most real estate managers are not investors and thus I wouldn’t take their advice as the be all and end all.