Stephen,
I really feel your pain on OSD for Pixhawk and Cube. I am an Eagletree Vector FC user and the OSD on this FC is what I would consider the “Gold standard”. Unfortunately, Eagletree has gone out of business and I am switching to Pixhawk, but cannot find an OSD (that is available anymore) with the features/capabilities. The ones mentioned on this thread are all, unfortunately, very very poor. I certainly would be interested in finding one that is available.
The one that I like, but I am not sure is available is XtremeOSD: http://www.xtremecopters.com/home/index.php/products/ct-menu-item-5/xtreme-osd
Another that looked promising is AlceOSD: https://sites.google.com/site/alceosd/get-one
But I am not sure if any of these companies are selling anymore. It seems like the OSD market for FPV is disappearing.
Chris