BTW, many thanks for your interest in the blog article and the Excel comparison sheet.
The blog article from 26/06/2016 has been accessed over 31,600 times.
The latest version of the Excel file (from March 2025) has been downloaded over 1,100 times.

Have you considered also specifying preamp and DAC chip models as you did in ADI-2 series comparison?

No.
It was not the intention to add all RME products, only FW, USB, TB based recording interfaces.

For ADI-2 series of USB based reference converter, this gives you a good overview:
https://forum.rme-audio.de/viewtopic.php?id=32506

I now proceed in such a way that I delete all factory routings and only configure the necessary ones. If I additionally hide all the channels that are not required (channel layout), everything fits conveniently into the matrix overview without having to scroll through it. This gives you a fantastic overview of all routings and makes it easier to maintain and troubleshoot TM FX snapshots / the routing.

With one screenshot per TM FX snapshot, I can also document the routing of the various snapshots in the best possible way. The whole thing would not give this excellent overview via 2 matrix views and would also unnecessarily complicate each check of the routings.

I've also worked with 2 recording interfaces, RayDAT and UFX as a mixture of converter and preamp. So I know how it feels and how much more complicated it is to handle. My recommendations (and please understand them only as such) are based on all these experiences.

I get your point, but tbh, selling RME components is easy, there are many people who are happy if they don't have to pay the full price and can buy a used unit in good condition.

For me, it is important to have an optimum in terms of workflow and operating / maintaining the environment.

You are more flexible in creating monitor mixes as everything can be routed through the internal matrix with only the converter latency. With two devices makes routing more challenging and cumbersome. In some scenarios you will have to route channels between the two different recording interfaces through the DAW with the full RTL. The one digital ADAT I/O of the UCX II supporting only 8ch at single speed won't help much.

Another (IMHO) disadvantage is, that with the 802 FS you do not have the possibility to digitally save and restore all channel settings (mic channels and phones).

Furthermore, in cases if you want to use stand-alone features, you will only have it more tricky when having to operate two units separately. Especially if you should need to operate / change routing on the display.

Finally, you are with MADI much more flexible. Number of channels / devices allows for more grows. Much more possibilities to distribute devices across rooms using multimode fiber. More spare channels in TotalMix FX for special routings, monitor mixes and mixes for loopback recordings. You can add converters with higher number of ports and having the same type of converter with the same converter latency over ADAT, MADI.

When using e.g. 12Mic (which has no MIDI port) you will need MIDI over MADI (which you only get with MADI) to remote control the unit via Auxdevice support. Workaround is to use RME connector in combination with LAN connection, but this can be more tricky in life scenarios compared to the possibility to use MADI are multicore and to run remote control over it.

Based on my experience and running a quite flexible setup with a lot of functionality, I would always recommend UFX III instead of a combination of multiple interfaces to be open and more flexible for new demands.

Maybe for your application this is sufficient, but I still could imagine, that working with one unit and having the flexibility of MADI brings more features and value for you in the long run.

If, then I would sell the other units to cross finance just right now when they are new. Chances are high of reaching prices in the range of 75-80% of street price.

Just my $0.02 on this topic, your mileage may vary.