I understand the thought process behind the belt they are lower maintenance in theory and a bit cleaner and quieter. although i never heard my chain much over the afermarket pipes.
if your main concern as it sounds is your wheel cleanliness look into a lube that doesn't sling such as chain wax. This is what I use on my speed triple and I never have lube on the wheel when i clean it and i do quite often. Albeit do to the design of the speedy it's not gonna get much lube on the wheel anyway. For te most part you'll always pick up road grime very quickly so your stuck with cleaning the wheel. My suggestion is a good wax if it's a powder coated wheel. makes cleaning the wheel much easier.with a good wax job you can literally wipe of the grime with a towel and have that pop back and for the shine a quick detail spay.
Common sense. So rare it's a god damn super power.