Generally, if you have to go and ask a TSA official whether the item in question is okay to bring on the plane, they get a little skiddish. I was trying to figure out whether or not I could bring my rope as a carry-on since I needed to cut weight on my checked baggage to avoid paying the heavy bag fee. The TSA guy had to get his supervisor to check, and the supervisor told me to leave the rope in checked luggage. Many of the officials aren't familiar with camping gear, so they end up applying TSA policy as broadly as possible to cover themselves/their jobs.
I brought a ton of gear from Boston out to Mount Whitney, and I had my bag searched both ways. True, it can be a risk, especially considering my entire trad rack was in there, among other things. But I did not want TSA people to get weirded out by a large metal mass with a ton of wire-looking runners attached to them in a carry-on; a rack is way too expensive to lose... Like Vitaliy said, the convenience of having the gear on you has to be weighed against the risk of getting stopped and forced to check the item... or worse, having it confiscated. If you're not direly trying to avoid overweight baggage fees or something along those lines, just check it. You can take one little countermeasure for protecting the gear by packing stuff like crampons and/or trad racks in stuff sacks and packing them underneath/in your clothes/less important or generally compressible gear. Also, you could keep a list and dated photos of all your significant gear that you check, too. It may seem excessive, but it gave me peace of mind knowing I had some form of backup while sitting on the plane for hours.
So what I'm saying is, I guess, that even though there are some lax airports that you can luck out in, the general trend of the TSA is excessive safety, sometimes to the point of paranoia (some TSA official was sure she saw a bunch of liquids in my pack, and she was difficult to convince otherwise even after another security guy went through my pack by hand...). I wouldn't test how flexible they are with their policies, it will only leave you with headaches. Air travel just likes to do that...