If its just about Spidf then it doesnt matter if its an Interface für 200 or 1000 Euro cause its digital?
Well (for me anyhow) it's not "just" about SPDIF but that was a big concern as I like recording direct with the Kemper and SPDIF delivers a nice clean level each and every time no matter what amp I switch to. I found that by using the main outs and trying to get a balanced DI between different rigs was near impossible, was always having to tweak the clean sens or what ever setting to get them to match., big headache.
A majority of the interfaces did not have SPDIF and having a few nice pre's are quite important lol.
Anyways, I am really happy with the RME so far and having the ARC controller for a few days I now have a nice control room setup and can switch speakers and route sound pretty easily.