Part of the rewards in this 2 weeks season are Talisman that you cannot get anywhere else in the game. It is a 3-set Talisman. So it makes absolutely no sense to get 1, 2, 4 or 5 of them. I reached the rank where you will get one set (but all the same subtype, which I don't like) at the end of the season. It was ok to do this, of course it did cost some SoW but not too much to do it in 2 weeks in my opinion. But to get 2 sets of these Talismans you would need to get to tier SSS and be ranked top10-50 ...impossible for me and probably for more than 90% of the playerbase.
Apart from reaching AAA for the 3-set, the lower sweetspots in my opinion are:
Tier D -> 2 rare souls
Tier B -> 2 skill shards
Tier A -> 3 heroic souls
I had 2 game crashes in total. This is not much, but it is severe, as you lose the SoW and the used chars for your next try. Apart from that, everything runs quite smooth... but yes, not very surprising, as it is more or less the PvP environment with a different graphical design...