Actually, this may not be the best strategy in all cases. I would rather have awesome loot at the level I am running, than loot I can't use for another 2 or 3 levels. In fact the zone I am really looking for loot is 14 and 15, i.e. things that can be used by a fresh iconic -because of XP banking, I spend a lot of time at these levels, and by 18 I am decked out in named gear anyway. Bumping the loot tables to the 16+ range is counter-productive to this goal.
I just started a new iconic life and bought a stack of the potions. Running a potion really makes a difference to the number of blue light chests I am seeing. At least 1 in 3 are blue. It looks like almost everything is just masterful so far, but maybe the stats are a little higher in general. I have seen 90 spell powers at level 14, which is pretty solid. I haven't found anything I would keep, but they are selling on the AH pretty well so they must be useful to someone.
I also noticed an interesting effect. When my partner opened the chest it would show the yellow light. But the instant I looked in the chest the light would change to blue. So that might be useful to people trying to game the system by having others open chests on your behalf. It won't work :-)