Honestly lemme give u the unbiased opinion(since i use madara 5k), both are good, in their way of playstyle, and both have different synergy depending which ninjas you have, now keep in mind, madara 5k completely denies any buffs / mysteries from being pulled or had and doesnt get chased pretty much like edo itachi, while edo itachi just denied shields, buffs, have a reflect mirror for every round starting and puts ur target into a "dream" state, which is basically a sleep 2.0, with that said, i think it comes really want and what ninja you have, i think meta is what you make of it, in this case with top 10 have mostly, team wise, keep in mind also, there's a counter for every ninja used in this game, if you're looking to just have fun, just go with ur favorite ninja from the 2, if ur competitive, i'd say any of them is good, and have good kits.