personally I'd go for the Fisher. Probably less complicated to work on, and if I had to bet on it, more power as well. The Philharmonic was one of their entry level units but its still nice. German stuff performs well, but its not always the easiest to work on.
That said, you might get lucky and find the Grundig has the NF-20 push-pull EL84 amp, and those are apparently something very special.