In reply to Owen W-G:
only disadvantage of dry treatment is price (as far as im aware, the treatment can help keep dirt out as well)
and possibly a smidge of weight
re 60 vs 50 - cut 10m ooff (or 2 x 5ms) plenty of uses for the offcuts !
i hadn't seen the obsessions but if thats 110 a pair - i'd buy em (if i needed any),
i have a pair of 8.3 shorties (30 m) that have been fine