Triple Turn-in Trap

[Simaril]

If you are turning in HQ items on your triple turn-in leves, then you are getting a 600% experience increase, and no single turn-in leve gives you six times as many experience points (it would only be 200% if you turned in HQ items, and the exp rewards are not anywhere near that difference). The HQ turn-ins are what make the triple turn-in leves so valuable. If you are not confident in your abilities to regularly HQ the items that you need, then, yes, stick to singles. When you can HQ with regular success, then switch to the triples.

I HQ pretty much all the time.

A triple turn in requires 9 items to get 3 rewards.
A single turn in requires 1 item to get 1 reward... so 9 items get 9 rewards.

If the reward is 10,000xp, and you turn in HQ you get 30,000xp.

(tripler) 3 rewards X 30,000xp = 90,000xp for 9 items crafted
(single) 9 rewards X 30,000xp = 270,000xp for 9 items crafted
In many cases the items are VERY similar

HOWEVER, the tripler gives 90,000 XP per leve, while a single turn in is only 30,000 XP per leve. Single turn ins are a "waste" of leves, but more efficient use of materials and time if you have leves to waste.