ePMP 4600 - Short or Long GI?

I know you potentially get more bandwidth using a Short GI vs a Long GI. ePMP 4600 seems to default on Long GI.

I was wondering what most everyone is using with the 4600 Long or Short. I would assume short due to low interference levels and the ability for more bandwidth.

How about on frequencies with more interference like 5.7ghz? Do you do short or long?