I take nothing away from Aimpoint. Good product. I read extensively on the SPOT before buying it. And the reviews have been shown to be true. It's rugid, well built, holds zero, easily visible in daylight conditions, and works well. I recall seeing on the AR forum a video of a torture test of it versus Aimpoint and it faired as well as the Aimpoint. I wish I could find the link. I'd go to the AR forum and ask for it. It also came highly recommended from a guy at the range that I frequent, who had it on his AR.
Where it falls short of Aimpoint is the coating on the optics, which was also stated in the reviews that I read. The view through it has a slight bluish tint. In daylight, it's not noticable. In dark conditions, it is noticable. It's not objectionable, IMO, but it is noticable. For me, the difference here is not worth the delta in cost of jumping up to an Aimpoint.
Lastly, it's not a "cheap" clone. You might be able to get one for around $160, if you shop.