Several issues. Far too little xp for winning makes buying 4th and 5th tier upgrades too much of a grind. Being forced to surrender due to connection error when my connection is running at 200mb/s constantly at full bars. Opening one gold chest requires me to win 20 games. Which will force me to either open the chest in slot 1 or get rid of the newly acquired chest. The first several arenas are too easy to blow right through as you only need 5 wins. This causes you to be severely lacking later.