I've just found an interesting option for managing my arrival day in Frankfurt (not till next June.) Frankfurt airport advertises a private service called bagshuttle.com, which will take your bag from the airport to your hotel so you can do other things before heading to your hotel. It's not super cheap (€40) but might be a nice treat so I can squeeze in a bit of sightseeing or a meal without my luggage before the hotel's later check-in time.
I know you can do this all over Switzerland with sbb, but I haven't seen this in Germany before. Is anyone familiar with this outfit and if you used it, did it work out well for you? I hunted for reviews online but didn't find any.
I could just take my bag to the Hauptbahnhof, store it there and be on my way - cheaper and not difficult. Just looking at alternatives. Of course it's a small carry-on only.