I posted the following on the bmw site regarding a comparison between an RT and GW...but the maintenance is the same;
Every bike is a great 3000 mile a year bike. But...
there is no comparision between a touring bike like a LT or Goldwing and a SPORT touring RT. The differences should be obvious such as comfort; including seating, 2 or4/6 cylinder engine, electronics; including radio, intercom, cruise, reverse, and of course, storage. What you lose is some degree of SPORT, but not too much. The real question should be LT or Goldwing.
In my opinion there is no better TOURING machine than a Goldwing. Designed for that sole purpose, it excels.
TOURING means miles and miles, day after day. Honda's advantage over BMW may be subtle but very important.
Smooth and quiet. A low center of gravity flat 6 engine turns 3000 rpm at 70mph.
Average 40mph on regular gas. Service intervals matches it's TOURING purpose. 8k oil and filter, 16k spark plugs, 32k valve inspection (my GW has 132K and the valves are still in spec, 16k tires, 32k brakes), discount parts are the norm not the exception. Cost per mile and dealers on every corner are important when TOURING.
Factory warranty is 3 years and UNLIMITED MILES with an option to extend the factory warranty and additional 4 years (7 total) with UNLIMITED MILES. My last Goldwing had 248,000 miles and I wouldn't have hesitated to hop on it to Las Vegas for dinner.
Everyone is happy.
You really can't compare a SPORT BIKE with bags to a TOURING bike. Give up a little of one for the other. I couldn't so have both. The RT is a good casual touring bike but a great SPORT TOURING bike. The Goldwing is a great TOURING bike with manners in the twisties.