I don't necessarily agree about the "too too", tho' I think that Riv could have made them as strong and useful with a "coarser finish", but I do agree that the old Nelson/Camper/Junior type look better, to my eye at least.
But!! There can be no question for one who has used a Sackville Medium that the SM is a more **efficient** design: that is, it can carry more with less saddle-to-tire clearance, and by spades, compared to the Carradices and the Bagginses. Again, in my experience, the SM can carry almost as much as the Hoss (and far more than the Camper) while requiring far less clearance; and the SM loads easier than the Carradice types and buttons up easier than the Baggins types.
(For the record: I've used several each of the Juniors, Nelsons, N Longflaps, Camper Longflaps, and one each of the the smaler Nelson -- forget the name, the Adam, the Hoss, various home-mades, and now the SM, as well as various Bagmans and SQRs and other mounting kits.)