Definitely we recommend ZPL for several reasons. One is it is the language Zebra is committed to continuously improving. The other languages are only supported for bug fixing. Two, it is the language with the best font and localization capabilities so if your business takes your apps to other countries, the printer is right there with you. Three, it is the one language that is shipped in nearly every Zebra printer so you can shift from one to another without changing your app.
CPCL is easier to program for mobile receipt printing, but that is the only real benefit to it. EPL is seen primarily as a niche product with a limited number of customers.
Hope this helps,
Thank you for your quick response.