If you can somehow get your hands on an RMJ Talon I'd highly recommend buying it, regardless of cost. Or a Kestrel if you plan on carrying it on your person. The Talon is simply the standard by which other tactical hawks are measured, for reasons given above by Two Hawks. But if you're ordering one now, give the company a call, so you know what to expect. You may wait a year, or they may send you one next week, but finding out where you are on the priority list will help you make your decision and prevent frustration later.
ATC has historically been a decent quality product, and O-1 in the mid 50s RC should hold up well. They are fine light-infantry carry hawks although some people have complained that the handles will loosen up with heavy/extreme use. That should be expected though (metal v. wood or plastic), and if you expect more infantry type duty than crash/rescue duty it may be a good choice.
If you are comparing RMJ and ATC, you will also do well to check out K-5 Tactical. The current K-5 spike hawk may be a bit heavy for light infantry day-to-day carry, but is as good as it gets for a crash/tactical hawk, and the sheath is bombproof. Look for the next K-5 run to be lighter, and if you can get ahold of Eddie and explain your situation he may just get one out to you before he introduces them at SHOT. He's notorious for being a great guy, with excellent cusomer service, great communication, and a well priced high quality extreme use tool. Way to lead by example, Eddie!
Also take a look at Ranger Knives RD hawk. They aren't up on the web site, but are available for delivery. You may find pics if you search here, but definitely at knifeforums.com. At 12" they may not be big enough for crash axe duty, but are excellent for infantry/sniper/scout type work. A lot better than the Kershaw camp hatchet I carried for several months in Afghanistan anyway, and more than three times less money than an RMJ Kestrel in the 12" size category. Just don't expect it to pry doors open like a Kestrel. On a personal note, as a contractor on an all-elite PSD team in Iraq Justin has proven himself in combat, with guns as well as welding torches(he supervised and built our armored Suburban), and has watched my back and my teams back for hundreds of combat miles. I support him anytime I need custom combat tools. And his products have proven themselves as we tested the hawk he made for me by cutting through a c-pillar of a car in baghdad, with very little effect to the edge. His own hawk, pictured on his website, held up as well, and didn't take any edge damage until we started hacking concrete curbs with it.
Best wishes,
JB
What I carried and will carry:
Kershaw camp hatchet carried on LBE/assault pack in Afghanistan (I wasn't a BF member back then...)
Ranger Knives custom S-7 Axe in the truck and Busse Battle Mistress in my assault pack in Iraq
RK standard entry tool in my car right now
RK RD Hawk on my assault pack right now
K-5 SpikeHawk in my truck right now
RMJ Talon sitin in the back room, 'cause it's the most fun to play with