Is GeCube a good design of the 4850?

http://www.landmarkpc.co.za/store/ [...] -1921.html

It uses the standard AMD standard design of the 4850. It has all the strengths and weaknesses of it.

Is the Gecube 4850 better/worse than the HIS digital 4850?

Is there a way to tell?

As stridervm said, they are the same reference board so they are identical.

If I was you, I would go for the cheapest one offering the best warranty. I know for a fact that HIS only offer 1 years warranty so I would stay away from them, unless it is cheaper or comes with a third party cooler (not in this case though)....

VisionTek, lifetime warranty. Anything else shouldnt even be considered.

I don't think you can get VisionTek from where he/she is....