SteriPEN Traveler Mini DEAL!

Looks just like the AdventurerOpti but different color. Wonder what the difference is. When the AdventurerOpti came out, a lot of the reviews said it was the most reliable SteriPen to date, that they had been glitchy in the past.
The only difference I could see is the "Opti" technology which means that the new SteriPENs have an optical sensor so that they only turn on and off in the water. The original versions have two metal plates instead of an optical sensor. I haven't read very many reviews though.