I have 3 AR varminters intended to shoot lots of small varmints. Two of them are in .204 Ruger (one for sale as we speak) and the other is a .223. All of them have 24" varmint barrels (.920", not those wimpy HBARs) and they are heavy. The weight is not an issue for me since they are bench guns. However, if you're looking at a real varmint barrel and intend to carry the gun a lot, I'd stick with 20" and consider fluting.
Bear in mind all that terminology and camo paint is no more than marketing. It only has value if you like that kind of stuff.
I like the idea of the Predator RRA or Bushmaster series. But I'd likely add a bi-pod and likely shoot prone so weight wouldn't be as big of an issue, unless we are chasing a prairie dog town. Not in love with the look of stainless, but not totally opposed to it either.
RRA is a great brand and they have extremely great customer service!!! I have a 20 inch NM A2 that i shoot comps with and I had a problem with the FSP and called them up. BJ had UPS at my door the next day to pick it up! I got it back in exactly 7 days to the day from when I shipped it out and it was fixed at no cost to me! When I called they were very courteous and gave me no problems at all! This shows me alot when a company provides that kind of CS for no cost to the consumer and they had it picked up and the scratches that were on it were not there when it came home which was another plus! I highly reccomend RRA not only for their quality products but for the great people who work there too! The predator pursuit would be an excellent varmint rifle! We have sold several and have not had one come back yet fwiw.