I've owned nothing but Suzuki's since 1996 (4 of them) and I've only ever experienced the usual Suzuki problem of the dreaded CLUNK in to 1st - plus the dodgy electronics of the mid '80s
Granted the first to bikes were only a GN250 and a GR650, but both of them had fairly high k's on them, the GR was half round the clock for the second time. The GSX600F had well over 100,000km on it when I sold it. Granted it did have a bottom end rebuild at 80,000km (before I bought it).
I've know got 31,000km on the 02B12 and the only thing that is starting to shyte me is the damn vibration between 3500-5000rpm. I must remember to tighten the number plate up - that's what's rattling the loudest.
But never a problem with a whine from the engine or gearbox......
However, I would have to suggest that, unless you trust this mechanic with your life, you get a second opinion.