I voted a even mix of both, but i want to add, i hated the three unique dragons event, which was based on luck only, if you didn't get the drop you missed out. i didn't get the third despite putting in considerable effort, and although i had the gems i refused to buy it/the mats. i made it a challenge to get the events done with out large outlay of gems, or fail it. that is still a sore point for me.
A luck based event with a time limit was C R AP.
Another point is the neighbours request. Slowly getting a group of good neighbours so not too bad, BUT i would rather that on future events, we ask for neighbours help FIRST, then allow us to catch up for the rest of the event, NOT at the end when neighbours replies can be slow, that's also a big pile of manure.