Keith,
Alot of prone shooters wonder that openly. Bleiker has figured out that using custom barrels will give them a big advantage over other Olympic prone rifles (Lilja).
But, there are a few contenders in that ultra-expensive rifle class.
Anschutz has their F-27A Challenger rifle, which uses a single-shot straight pull action. They are said to have a "Select" Anschutz match barrel. I'm not sure what that means, but they do some extra effort at the factory to pick their barrels. This rifle has had some mixed reviews, and is built out of the AHG side of the family.
http://ahg.anschuetz-sport.com/index.php5?menu=54&sprache=1&seite=83&produktID=607
I have a pair of Eric Uptagrafft's new actions that have twin front lugs and a 6 o'clock FP. His new rifles will use Shilen 4R barrels and should be very good.
The down side to Bleiker is that if your rifle takes a dump, getting service and parts will be a bit of a trick. They had a recall on their centerfire rifles, but I don't know the outcome of that. I think their trigger group alone is running about $1000. Have fun replacing that!
I'm guessing that Peter is talking of Warren P. as the "top shooter." I think Matt Emmons with his Lilja Barreled Anschutz 2013 would have some interesting insight to this, as well as Raymond D. with his Feinwerkbau. There is also Aurthur A. with his Walther that is another great shooter (gold in Bejing). Many more as well.
But, Bleiker is seen at the very top level, they did very well in Munich at the World Cup event, but I would suggest that's a matter of barrels and not action design.
There is a big revolution underway in Olympic rifles, and I think Eric is on the right track with learning as much as he can about rimfire BR and using those ideas on his new rifle.
Here is a link:
http://www.bleiker.ch/KleinkaliberSmallbore_3.html