I have whistled quail up into the yard without a call many times.
Jim Mathews out of CA makes custom quail calls. I've seen them in person and have spoken with Jim a few times. His calls are beautiful. Expensive, but beautiful. They aren't as easy to use as the Loman's call as Jim's calls are in two pieces held together on one end by a leather lanyard. They sound just as good as the Loman's call.
If you are looking for simple and very effective call that will last a lifetime, go with the Loman's. I don't leave the house without it.