I saw this the other day. I meant to sit down and compare the specs to the Aurora Design module that one can use with these old radios. The one I have sitting around here has a 4x45w into 4 ohms. Like the new Retro Manufacturing radio, it has Bluetooth and all the such-and-such. This seems to be a bit more capable than the Retro unit, though of course the Aurora costs a bit more -- still less than a fully-refurbished standard Becker of any sort. Nonetheless, 25x4w is a bit anemic, and that spec really should be at the top of the bullet list rather than all that other stuff. The other two aren't even worth considering, one might as well just get a few external bluetooth speakers and a delete plate. Truly, if I didn't have a hole cut for an antenna, I wouldn't have a visible radio at all, instead opting for a totally hidden sound system.
Anyway, an Aurora conversion is $750 right now but you get what you pay for, up to a point. Nonetheless, I appreciate Retro for even attempting this, and it is better than many of the other non-Porsche Classic new units emulating the 50s/60s radios out there right now.