IYM,
Niether of the two howlers you have now are bad, but neither are what I would consider an "easy driver".
If you can drive either of them, you are doing well, and a custom howler wouldn't be out of the question.
Yellerdog's Howlers are very easy to drive, and will have a similar tonal quality to the Red Desert.
A Cronk Howler is equally easy to howl with, but the addition of a cow horn adds tonal quality few wood or plastic howlers can get, and buffalo horn is supposed to have the best quality of all.
A howler from BradH, with it's artwork, and a mouthpiece made from the horn, is another way to go, with so many "features" going for it the value is easliy justfied.
Your biggest decision in howlers is size. You can have large "war horns" that practically take a backpack of their own, on down to a modified CritR Call that can easily be lost in your pocket.
There are advantages to both.
Proficiency is best learned by talking to the coyotes themselves, there's no better teachers.
It's more about what you say, than what you say it with.
Krusty