Check in was fairly painless, some limited English (but better than my German, so can't complain). Hotel is clean, charming, and modern feeling. The attached brewery does some excellent pork knuckle and similar fare. Lovely little spot by the river and just 20 minutes from the Frankfurt CBD.
Only complaint is the shower; there's no barrier for water so it justs floods out of the shower, into the bathroom, and on into the hallway. You'll be mopping up after every shower. Probably fine for a solo traveller, untenable if you're sharing with someone.