Replacing stock 1977 A6 AC compressor

[gramps77]

Ive searched here as well as google and trying to replace the compressor.

On more than a couple of occasions, I see NOT to buy rebuilt as they "dont last long".
What about the newer aluminum bolt-in replacements such as these? http://www.oldairproducts.com/catalo...120132081.html
Has anyone ACTUALLY used them? and by that I mean, in YOUR truck not what someone else has said.
For whatever reason, there is a lot of 2nd and 3rd hand info that gets passed around on this subject. Thanks for any input.