Nuremberg's modest airport, with no direct long-haul service from the US, means every business class from Columbus to Nuremberg itinerary routes through a major European or East Coast hub, and after dozens of these connections I can say the routing matters as much as the airline. The factual baseline: there's no nonstop option from CMH, so Delta, American, and United all funnel passengers through their transatlantic gateways—Delta via Detroit or JFK into a European partner hub, American via Charlotte or Philadelphia connecting through London or Frankfurt, and United via its Chicago or Newark hubs into Frankfurt or Munich, with a short regional hop finishing the journey into Nuremberg. Total elapsed travel time typically runs 12-14 hours door to door, though the marketed transatlantic segment clocks in around 8.5 hours.
My preference has consistently been United's routing through Newark, where their Polaris business class delivers lie-flat comfort and a reliable Saks Fifth Avenue-designed soft product, then connecting through Munich or Frankfurt on a Lufthansa or United Star Alliance partner segment into Nuremberg. Delta's strength lies in its Detroit hub efficiency and Delta One suites on widebody aircraft, particularly the A330-900 with full-suite doors, though you'll want to confirm equipment on the transatlantic leg since regional aircraft handle the final Nuremberg connector regardless of carrier. American's Flagship Business Class, especially on 777-300ERs departing Philadelphia, pairs well with a London Heathrow connection if you don't mind clearing UK border control mid-journey. My insider tip: build in at least a 90-minute connection in Frankfurt or Munich, as both airports require passport control re-entry into Schengen even for connecting passengers, a step travelers routinely underestimate.
January through March and October into November consistently offer the softest fares on this corridor, as Nuremberg's Christkindlesmarkt crowds (peaking December) taper and summer leisure demand hasn't yet built. Given how these connection-dependent premium fares fluctuate week to week, setting up automated fare tracking for this specific routing will save you from chasing prices manually.