Shroud of the Avatar's development notes that one of the big issues plaguing the game's 10th major update was stability. That means that the team needs more people connected and playing (or trying to) so that the issues can be documented and solved.
The team also introduced the Challenge Dungeon to get a clearer picture of PvE combat, noting that it had become a bit too single-note even against different sorts of enemies. PvP, meanwhile, is a matter of constantly moving, which is very network-intensive. The update discusses some of the patches planned to address both issues in the future, including better enemy AI and skills reworked to not make constantly darting about the most attractive update. Take a look at the full developer dispatch for more information.