Hah! I was just about to recommend the Vipar and a couple of postings showed up!
The XS-1500 Pro is a superb light for a 2' x 2' tent and, short answer (I need to get back work) is the Vipar is a better quality product but the mystery light will put more light into your 2' tent.
Is the driver for the mystery light detachable?
What's the make and model of the mystery light?
