The jon is more utility oriented, it's easier to load in a pickup and move about because nromally they're a good bit lighter than a V. On the other hand a V will ride much better on flat water, and for your smaller boats, say 14' and less, the V will be more stable. Both have their place for sure, a V is generally higher price wise and can be as much as twice the price of a similar size jon.
In the Jon boat side you have riveted and welded, and also a few companies that have made poly boats. My first Jon was a 14' 32" boat and it served me well for years on the river. I had a 15hp evinrude on it and it would fly! I eventually traded up to a 15' 46" and felt like I had moved into a castle! Keep in mind they're just like a basement or a storage building, no matter how big the boat is, you will aquire enough stuff to fill it up!!
Eventually, you'll run out of room in that boat and you'll get a bigger one, and then you'll want both a V and a Jon, etc. You may not believe it now but trust me, it's just how it works!
If you're married then prepare to spend twice as much, you'll have to buy her something every time you buy the boat something. (They're in competition you know).
Seriously, good luck, I'm sure if you love to be on the water like I do then it doesn't matter. You could be in a washtub and manage to have a good day!