RME is one of those companies that has a reputation for creating rock-solid equipment for both live and studio solutions.
I use this device as my “plug-and-play” record device. It is a 64ch @ 48kHz MADI to USB interface. It easily fits in my backpack and is bus-powered making it the perfect multitrack solution at monitors. Sometimes I show up at a show and decide it would be worth having multitracks to playback for either a future gig on different gear or just a reference for some reason. I can quickly pull out any laptop, plug the MADIface in via a USB-B to USB-C cable, open Eclipse, and within 60 seconds, I am recording up to 64 channels at 48kHz.
RME plays very well with both Windows and Mac. The drivers are always kept up to date. There is also an accompanying software called TotalmixFX, but it is not always necessary as this is a class-compliant device. It can even be used as an Optical <> Copper MADI converted when supplied with power from a typical USB power brick. For only slightly more than the SSL converter, I would pick this 10/10 times due to it also being an interface in itself and not just a converter.
MSRP - $999
Note: RME advertises their channel count as a total number between the inputs + outputs. You will see this listed as a 128 channel interface; which it is but only because it is 64 inputs + 64 outputs.
If you have any other specific questions, feel free to email me at josh@spacebearaudio.com