I would prefer ornaments.
That way I could use it on the gear that helped get me those wins in the first place.
Separate armor would take up more vault space, and honestly would just be redundant.
Why would I want to grind for good pvp stats on one armor set just so I can grind for good pvp stats on a trials armor set...
That's probably what will happen.
Bungie likes the grind.
Still doesnt make sense to me though. They could give the armor that drops good stat rolls and people would still grind it even if it looked bad because good stats are hard to come by.
Put a universal ornament in as a drop and people would grind for that too. Granted they would only have to grind until they get it once, but then a lot of people who just want the look dont care about stats so they werent going to grind for more than one piece anyway.