I just received a reply from WBUR:
"You are correct in saying that, even though the feed responds to non-SSL http:// requests, the underlying audio is still being served over SSL.
Unfortunately we don’t have a non-ssl version of the feed, but it is something we are working on. Unfortunately our hands were tied as NPR required our feeds to be https so we had to fast track that code and haven’t had time to get a non-SSL version working.
But your feedback has been heard. We will hopefully have a non-SSL version available in the coming months but I cannot give you an exact date."
This is a step in the right direction. Reciva radio owners apparently do matter.
I echo he comments of Solo2. Grace Digital is the only game in the US other than the Sangean portable. The others are European brands and I think the only brand available in the US is the Como but it is very expensive.