Personally having played a lot of NA and EU. I consider both fun even though I have high ping on NA I don't think the melee speeds make EU/NA worse than the other. Both speeds have its upsides and downsides. Medium might feel slow and Fastest might feel spammy. I don't think either side is worse because of the melee speed or better. Any argument saying that fastest is pure spam and that medium is too slow and boring is just because it's unnatural to the other side. It's just different, not better or worse.