OK, thanks. I've just enabled it on my system (12k bps) with RFM69CWs and they seem fine right next to each other with dipoles.
I assume there's no great current hit with this option? Also, if it's an LNA on the front end presumably it reports a higher RSSI rather than dropping the noise floor, this appears to be the case from what I can see but it's difficult to tell.
Mark.