That's two more to add to the list.

Quieter (proved by asker).
Less breakaway (opinion from Hurdey).
We already know 17"s are:
Faster
More comfortable
Cheaper (and tyres)
Much easier to repair
Less likely to kerb
No white worm
I wonder how many would have chosen the 17"s if they came in the same
finish (with black inserts) as the Monza shadows??