Are HD cams over rated compared to Mini DV? Puzzled

Okay folks:

I have a Sony VX-2100 cam (and no at 54 I am too old to be a skateboarder... grin..). I recently purchased a DVD from an award winning couple that do nature films. They used to shoot in 16mm and then painstakingly create this into DVD's for sale.

A few years ago they purchased a Hi DEF video cam and continued shooting similar wildlife footage. I just recently got a new wildlife DVD produced by them. I was surprised at the amount of "noise" and grainy quality of their new footage. Much poorer than their old stuff.

As a matter of fact I dont want to be unkind here but every Hi Def footage I have seen seems less in quality than the footage shot with my Sony VX-2100 on mini dV format.

What am I seeing? I dont get it... Perhaps old Hi DEF cams in action or???? To make things even more confusing, I watched a film called Parrots in the Land of Aus. Shot with extremely expensive high def cams and the footage is mind-blowing. You can see the nostril hairs on the Palm Cockatoos! As a matter of fact the producers of the film wanted to show off the capabilities of Hi-Def technology. Can someone explain this a bit for me? Real puzzled...

Thanks for the imput!

Cheers!

Don Kimball