Hi Java Green, I think your best bet would be to ring Minispares direct and ask for whomever knows the most about the gears. I have used both the MS S/C drop gears and MED's sets also - separately not mix and match - but only for racing ( full helmet)
I was hard pressed to find many if any differences visually (I think MED maybe a direct copy or even the exact same rebranded) Both primary gears had slightly smaller oil openings at the base of the outergear compared to an older NLA australian set (KG engineering) that were finally decommissioned after at least 10 years of racing life. (the modified case they ran in suffered failure not the actual gears) but the MS lubrication system was effective without fettling.
Now to your question - relative noise. Again , I wasn't particularly listening for noises, and at 8000rpm there are other wonderful noises to accompany any gearbox noise.
To me they were not perceptibly different to the ear - loud and rattly in neutral and whiney off the throttle. I couldn't really tell you what they sounded like at 3800rpms over a long time as only the warm down lap would have been the approximate emulation to highway driving -and after 6-8 laps of full on noise they were certainly quieter than that. On a couple of tracks exhaust/engine/gearbox noise was limited to 95 decibels at 30 metres. Again not really comparable to running on the road, sorry.
So I would recommend them as S/C gears and did sometimes change ratios - but I couldn't confirm any quieter type claims.
