Now that the event is over, I think overall devs did a good job of making it a possibility to complete for us F2P players. I was able to finish the last boss on the last day. I I missed 2 days of play because of real world problems so I know for a fact, I could've finished earlier to grind for the chests. I was actually able to get more event cards this time around compared to the previous 3 events.
I was able to get 21 Epic cards and 8 Legendary. The previous events COMBINED, I only got 16 Epic cards and 1 Legendary.
I only spent 100 gems that I had saved up from daily rewards + the gift from the devs for the previous bug.
Looking forward to next event!
PS - Can devs increase gem rewards for the daily rewards? Currently if you play non-stop for the 21 days, you get a total of 40 gems. Maybe double that? So instead of 5 gems on day 3, 6, 10, and 13 we get 10 gems and on day 17, 20 we get 20 gems. The only way to complete an event is to at least have 100. Just something to consider.