I agree that it's probably going to be interesting. The great thing is the hubby and I are pretty relaxed travelers. We have vacationed at several new luxury properties over the years and know that sometimes the kinks still need to be worked out.
As I mentioned I'm in Germany regularly. There are two hotels I stay in, one being a well-known American chain and the other a larger German hotel company. Both hotels are very nice, but they for sure cater more towards their country's clientele. To me the most noticeable is the food and food choices. For example, breakfast where one has lots of scrambled eggs, bacon, sausage, etc. the other sliced deli meats, cheese, soft boiled eggs, etc. Both are lovely, just different. And at both ale cart can be ordered.
One thing that I've noticed in the very little info I have found on Riverside is the bedding is more American. Large King size bed with single king size comforter rather than the traditional German two comforters. The bedding will for sure appeal to more of an international market.
As for the language. I would say that all Germans in the travel industry speak English, so I don't see that being an issue for international English-speaking travelers.
I'm really excited to try this new brand and to report.