F5 Load Balancing Exchange 2013

When I first went to implement this over a year ago, I wanted to do iApp and tried iApp, but was having some inconsistent results that even F5 support couldn’t answer. So ended up doing it manually, but in my research I have just notice one thing, under my pool profile config, under “Action on Service Down” I have “None”…..do you know if this should be “Reject” or “Reselect”?