Friedrich was a great host & I would certainly recommend him. My train had a problem so I ended up being 4 hours late, but he was absolutely gracious about it & had a printed out map with suggestions for things to see & restaurants to try. Excellent prep & much appreciated.
The location is great - east/west and north/south trams & buses, with a U Bahn about 2 blocks away that has a direct stop to the HBF. There are lots of stores with a 2-3 block radius (apothecary, restaurants, smaller grocery store less than a block, large shopping center with extensive grocery store & a bunch of other mall -type stores & food court a little further, easily within carrying distance)
Notes: because it so convenient to public transport, the street can be a little noisy. It didn't bother me at all, but if you're a light sleeper, you might want ear-plugs (but that's the case with anywhere that has super convenient transpo). Also, the building is a 3rd floor walk-up so if you have trouble with stairs, that might be an issue. I'm in terrible shape & had no problems, but my elderly father would have.