Force300 to ePMP2000 Forward Compatibility Behavior

Just wondering what kind of results others are seeing with the forward compatibility setup?  I have a 2000AP running and a Force300-25 running  This is at my house for testing before rolling this setup out on the network.  I have clear LOS to the tower, good signals, SNR seems low though there are no interferers I can find (this is very rural).  I am seeing over 30% downlink retrans and my MCS rates are all over the place.  Force200 runs like a champ by comparison.  My MAC is 00:04:56:28:82:3E.  This is a 40Mhz channel.

I think the telling figure is the 22dB downlink SNR, second worst on the sector (and the worst has -81 signal, vs -63 for this one)  That will likely be the explanation for the retransmissions.  Also, keep in mind that the MCS rates will vary all the time, and unless there's actually traffic loading the link it will often NOT be at the highest MCS it can manage.

I'd take a look at the spectrum analysis and see if you can identify an interfering signal that is visible to the Force300.