As a pom now living in Aus i've had the majority of bats that this forum has advertised.
I was in Greg Chappell the other day and picked up quite a lot of bats. The nicest in the hands was a puma for $900. The second nicest was an aussie made predator for $300. I used to order so many bats over the internet, and sometimes I still do, but nothing beats going into the shop, picking a few bats up, bouncing a ball and making your decision. It just so happens that when I do that GN Aus are always in the mix. A big for me is feel, i used to be obssesed with looks and grains and now i purely base a bat on pick up and sometimes ping. Handle plays a big part also and the Gray Nics handles have been the best ive used thus far.
$500-600 AUD to GBP is a hell of a lot of money for a bat. But in Aus, that's relative to Salaries etc, so its probably why most of us out here don't really bat an eyelid.
Would i say they are the best bats I've ever owned? Probably not, that would be my G3 puma.
Would i say they have the best consistency across all the bats I've owned? Yes, i haven't used one yet and gone this is a plank.
Its all subjective. All i'd say is if you get chance, try one. That being said, I'd always say try a Puma/SS, try an RNS. Try as many as you can and end up like me with 15 bats and a very unhappy misses!