I have had a few false alarms with the Floodstop, especially in areas that are prone to get damp like the bathroom.
So I would be wary about the whole house supply being cut-off from one sensor, which might occur with a wireless system.
With the floodstop, the wires are also a bit messy, especially in locations where they cannot be easily hidden (behind a vanity for example).
So there are pros and cons to both. Without the risk of false alarms I would be tempted to go wireless.