What a stupid answer, sorry. Pvp should be balanced for everyone, and not only to those who have the time to invest in their virtual character.
Yes, pvp should be rewarding, but not by making you so much stronger over the people who arent able to compete.
There could be: Better mounts, more options for gear customization, slightly more powerful gear, etc etc. There are so many options.
Spending more time in a game and get more powerful is an excuse for free 2 play games, but not in games like this where everyone pays the same amount of money every month.