Noise and clunk are subjective terms. To a new wing rider it can be very disturbing and to a more grey rider its old hat. My 1800 and a few others I've been privy to ride with are all noisy from 1st to 2nd and after that its depends on how smooth the shift is executed and at what engine rpm. I was tending to shift too early under 2000 RPM, shifting above 2500 is a noticeable difference, and a habit to be formed. I find cold or fresh oil always quiets the shift noticeably but I suspect it is mostly in the Goldwing's dna. Really find the time to seek out a local wing rider with the same model and go for a ride along side and discus it with them, I think you'll find we are not alone and its more surprising to have a smooth and silent shift than a clunky one (at least to some extent!).
Tom, in Mountain Home, Idaho
2002 GL1800 (Illusion Red) Non-ABS, 128k miles
Retired Air Force
"Audentes Fortuna Juvat"