Google uses pagerank to give a site a ranking of importance. Pagerank is strange.
One thing to note is that pagerank is logarithmic-ish. A pagerank of 2 is a lot better than just the double of pagerank 1.
By far the most visited site on my server, this blog, has got a page rank of 3.
Other pages on my server which are visited sometimes like w-nz.com, board.w-nz.com have got a pagerank of 2.
Maybe google values xr12.com a lot because it is about one topic and is the only site about that topic and that is xr12.com, where this blog has got tons of links about practicly everything from very various sources.
Pagerank itself isn’t the sorting factor for google but rather the context, although pagerank still is an indicator. Maybe google values a few links which are very specific above tons of links about very different topics.