If you're asking will a cheap 5V box mod from madvapes vape the same as your glv2 the answer is probably. Ohm's law is an equal opportunity law and 5V is 5V. The regulator can make a difference. You might get a little more fall off or less battery life with one or the other. I wouldn't expect much difference though. Styling and durability are more of a consideration when chosing between them than how it vapes.
As tj99959 says, what you put on it makes a lot bigger difference. I will also say that watts is a good guideline for finding something similar but, equal watts does not mean same experience. Similar yes, but, there are differences. I get told I'm wrong on this sometimes but, it's true.