I'm also particularly interested for gridseed users to give the bfgminer included a shot as this is the latest from github.
I have two Gridseed 5-chip units, currently mining with minerd via Terminal, one device per minerd. I am willing to try 1.5.20b1 but would like some setting information. Also do I need to have two instances of MacMiner, one per Gridseed unit?