Some points:
* Genepro is a way to draw a family tree. It is first a sort of drawing program, second a way to store genealogy. Gramps on the other hand is an application to store genealogy, with a big emphasis on correct storing of sources. What use is it to know A is married to B if over a year you no longer know where you found that information and how reliable it is?
* To me, http://www.genopro.com/family-tree-software/ is not very readable without a course in genograms
* As you draw the diagram in genepro, it can be very complicated. My guess is most users will end up with spaghetti very fast :-). Don't you spend too much time trying to obtain a nice visual graph?
In Grampsr, you store data, and there is a report that uses that to draw a generic family tree. This will never contain the 'organic' feature you can have in genepro, but has the advantage of being deterministic. Layout reports are improved with every release in Gramps, eg, 3.3 has better descendant view, allows vertical pedigree view, ... .

So, it is all up to the things you require. As the starting points of the two programs are very different, they will suite different workflows.

The fact that the GEDCOM output of Genepro is so bad/weak is however a good reason to skip it in my opinion.