Ditto what Ronp said..
They are the same MES and Cajun Injector, just a label change.
The only thing I would be looking at would be are they the latest models. Masterbuilt now has Lowes & Home Depot as well as several other outlets selling their product, so check around before you buy, there may be a sale, and you might get a discount if you tell them you have a choice as to where you will buy.
You never know until you ask.