Don't know anything personally about the Austin and Halleck but have read it is a very good rifle. I do know something peronally about the Knights and T/C's and they are both excellent companies to deal with. I'm getting away from the Knights because I do not prefer to have to use a carrier for a 209 primer even tho they claim it makes it virtually waterproof. I own a Knight Wolverine, early version and it is one with a #11 cap. I did think about the Knight Revolution but I read a very bad review about it and here is that link:
http://www.chuckhawks.com/knight_revolution.htm
Then I got to handle one before making my decision and I had to agree with the review I read about it. I also emailed Knight about one particular issue I read somewhere else regarding blowback and they admitted it was a valid issue only in their first run of the rifles. They have since redesigned the breechplug and either eliminated or seriously cut down on the blowback issue. The Revolution came out late last year and I think I would have to wait for a little while longer for all the bugs to get out of it before I would consider buying it. The T/C Omega design is sort of what brought about the design of the Revolution but the T/C design has been around for several years and is an excellent but kind of expensive choice. Look around, there are a lot of great deals of less fancy but just as accurate and as good quality as the more expensive models. I don't know about A & H's customer service but I do know you can't beat either T/C's or Knight's customer service at this time. Plus, I've just had to deal with Navy Arms for a discontinued rifle and got an immediate response and assistance from them so I'll add them to the T/C and Knight list. Good luck in your decision.