I know this is an old post but I just wanted to add, that I love Carver's calls. I just ordered the 6 strictly business calls along with a swift call and the 21 days in Coyote Heaven dvd. The purchase was easy, quick delivery. All the calls sound great. I bought my father in-law a pack of his rubber calls several years ago. They sound good. I called in a couple with one of them. In my opinion his calls are very easy to blow.
Rick also sells good calls and I am sure others do to, it just that I haven't ordered one from them yet. I bought a howler from Rick but I haven't taken the time to master it yet.
I should point out that I can't do howls on Carver's calls either. I just need to practice the howl, but prey sounds are awesome.
On my wish list is a call from Rudy, the Red Fox P call that makes bird sounds.