The Alpha has been very good. You need to add a good external high DB gain antenna but it just works. As far as the double USB. We sometimes just put the first one in and I generally don't notice any difference. Sometimes yes but if you're at a mooring not too far from the transmitter it doesn't seem to make any difference.

Just gave my Wave RV system away as the USB plug got some corrosion on it. Enough to make it not work anymore. The Alpha works so well I see no reason to get anything else. Of course,,, I'm sure there is a lot of new stuff out there that I don't know about.