I very much disagree. I would not keep a single adult in an enclosure smaller than 2 x 3 x 4 ft. Bigger is better. Do not forget, these geckos reach one foot in size and are very agile runners which do explore their territory each night and love to run and jump.
In too small tanks they become obese, immobile and very agressive.
In large tanks they are agile and friendly lizards.

Hope that helps

Ingo