Yep. Now tested experimentally I am here near FRA to meet some people and also on a small weekend mattress run HGI-Hilton-HGI just to see how it plays out. Folks, it's excellent! Both hotels are in the same (huge) Squaire building on the top of long-distance train station, within walking distance from FRA airport, hotel entrances being only few steps apart. You can find descriptions of both hotels on separate threads here at Flyertalk, but in short - they both are very good European style Hiltons. If you need 3 stays for 1 weekend, get your ticket to FRA for Friday and return on Monday morning.