The problem with having new items with better stats is that people will complain that it becomes unfair since they would have an advantage so personally I am more favoured of having just cosmetics (which is also easier to balance).
A few years ago Wucas and I came with an idea to bring up a sort of rank & tier system, top 10 would each get points, the more points the higher your tier, after a month it would reset and based on your tier you get specific tier graded gear that you can wear (something like bronze/silver/gold like most games, some cool gear with different tier colours) and that would come down to bragging rights, basically the higher your tier the bigger the balls.
We can always start making specific clan wars related gear, weapons, dashes, jjangs and what not that you could spend on a 'clan wars shop(?)', the more cw you play and win, the more points, the cooler the gear.. more rare gear I guess?
We can always look at other games at how the reward players that play a lot of "ranked/competitive" modes in games, for League of Legends for example they reward with cosmetics instead of game advantages.
