Climbto350 recycles jobs to inflate their numbers, and continues to advertise positions even after employes have asked the ad to be pulled (because the position has been filled).
Other services are available which offer more. Not all services charge a fee.
I've ben hired off Climbto350.com. I've also been hired out of Trade A Plane, as well as JS Firm.
I'd strongly recommend steering clear of avjobs.com.
Planejobs.com has good information.