Okay so I took that direct Paris - Berlin ICE today and I have a few things to say, nothing groundbreaking or anything
The ride is comfy. ICE3 trains they use are really good. Maybe not perfect (the automatically tilting seat was annoying after a bit) but still really good.
The first part of the journey from Paris to Strasbourg is awesome. You zoom really fast, it doesn't get old to travel at 320 km/h.
But it only lasts 2 hours. 2 out of 8 to get to Berlin.
The remaining 6 are just rolling through Germany, being anxious about the terrible things that can happen that will leave you with a huge delay or a cancelled train (would DB dare to, on an SNCF-DB joint operation?)
Views are nice tho. Especially if you're a silly creature like me that doesn't really like to watch or listen to stuff while traveling and instead likes to just enjoy the ride, you'll like it
But on the German side it's really obvious this train is too slow
It was very nice to take it regardless :3