Few here in the fresco debate have distinguished between the different weights. As the weight goes up, so too does the scale/chunkiness of the fresco weave
From the dozen or so Minnis swatches I have:
9-10 oz: This is the lightweight stuff everyone loves. Small weave. I would feel fine wearing a navy fresco blazer from a blazersuit (convenience travelling), but I would probably look to other weights or a hopsack if you want something in a different color
10-11 oz: ...