The mixed rewards is what got me to just break away from the event. Useful rewards for me would be medals (as I still need expansions), forge points, unattached troops (not color guard, drummer boys, champions, or rogues; got too many) for the era I am in, goods, blue prints, reno or upgrade kits, or supplies. Useless rewards are gold (as if 57 million isn't enough), residential buildings (same reason as previous), boosts, non-event happiness buildings, Victory Towers (I got like 70+ of them things in my inventory). Every one else's might be different, however, these are my opinions of such given with the city I built. Every since this mix came up, I kept getting "junk" that I don't want or need and felt this is a waste of time.
The other bit has to do with the delay of time between the tested event and the release of the update of the app. Nearly 90% of my game time would be through the use of the app, to include testing. To even have a short period of time, it's not good enough to test (why even have beta on the server select screen if supposedly the test server doesn't have the test event fully released) or to get my fancy up to take it on the live server; also, it makes us feel like we're behind or that we have to be forced to be on a computer just to test.