While you do mention a couple of possible weaknesses of the Optimus G, I think you might be doing a disservice to the person you are helping. The reason is that for someone who is seeking someone's advice, there probably isn't much in Jelly Bean that will make a significant difference to them in real life. Also, I think the interface is fine, and offers enough customization to make most people happy with the interface. Each interface imposed by a vendor has its own quirks to work with, but after a few days things become natural (unless a person is emotionally committed to a particular interface) so what you find as ugly may simply be a response because you aren't used to the paradigm.
I think that based on the release date of the Optimus G, it is a shame that it didn't ship with JB. But frankly, other than wanting the latest simply because it it the latest, I don't envision any significant differences (for my usage) when the underlying OS version gets updated. Sure, there will be improvements, but unless one obsesses about not having feature X, people can effectively get along just fine with any relatively modern phone OS.
For a phone with the display, processor and other specs of the Optimus G that is currently available for $99 on contract, the question should be easy to answer.