I haven't used the EZ-pro, so my observations can only be useful in examining the problem before you, but you will need hands on experience (yours or someone else's) to get at the specifics .
First, a disclaimer: all the devices of a given type are more similar than different. A skilled photographer will make good images with any of them and the best one will not make much difference in the hands of an unskilled photographer.
Second, it is far more useful to see images taken with one light in your modifier of choice. Multiple lights, like post processing, can make it harder to see the results clearly.
Having said that, the Link provided above will give you useful information and leads to a review published on another site, which is also useful. One of them, in a different size, is compared against the Westcott Joel Grimes portable BD. The person comparing them prefers the Westcott JGBD for the images it produces.
A bit more searching will lead to a comparison of the Westcott JGBD against a Mola BD and there, the Mola looks like a clear winner to me (the photographer gave me access to the images and I asked several women who were not photographers--they felt the same way).
What does all this tell you?
1. If you really want a solid comparison, you need to look at images shot in consistent conditions. Guessing based on what it looks like and how it is built does not help as much as you would think. And shots under different conditions, especially by different photographers and, most especially with different post-processing, can lead you astray.
2. No matter what you get, if you learn to use it well, you will get good images. And, conversely, whatever you get, if you don't learn it well, you won't.
One other problem with comparisons: if the photographer doesn't understand how the device works, results can be off. For example: a BD generally should not be feathered on people, most other modifiers benefit from feathering.
That isn't to say you can't figure a lot from looking at images, just keep these cautions in mind.
I will suggest two courses of action which I think are most likely to help you the most if you can't get solid comparisons from a skilled photographer.
1. Rent if you can (unlikely in this case), borrow or order from a place with a generous return policy. Try it for yourself.
2. Look at images. If you can see someone getting results you like, you know they are possible with that modifier. Get the modifier and learn to use it. There is a lot to be said for the confidence you have that the modifier works--it helps you work through building the skills.