If furnished, more suitable for short term stay, since tenant can walk in with suitcase. Then to command higher yield over long term, with higher initial outlay, but do bear in mind the window of vacant period and agent fees(if any) everytime a change of tenant.

If targeting long term tenant, family style, maybe they prefer unfurnished where they will have a say to how they like it. Tenant tend to be stickier, will take care of your unit better. Of course, yield may be lower, but probably lower upkeeping cost too.
That's how I would rationalise. But have to consider all other factors.