Roughly half-way through the event and I've hidden about 100 eggs on each of my worlds, due to time constraints for being online. I've also collected between 400 and 700 eggs so far. I know I'm not going to finish the questline (unless a miracle happens) and I'm not going for the collector's reward. I'm fairly happy with the prizes I've managed to get from the eggs so far, and hope to get a few more things from the various chests.
To sum up the event so far, I'm not disappointed that I can't get the questline completed or that I won't get the collector's reward. I'm fairly happy that I've managed to distribute eggs relatively equally between the people I am 'egging' and I think I've probably been given a fair amount of eggs in return.
However, I have found the questline rather disappointing: I find it quite passive and without much challenge. I feel that I'm not so much earning eggs as waiting for them to arrive and I can't do a great deal to actively earn them. It is somewhat dependent on people being able to be online at intervals during the day in order to use 6 hiding actions and then accumulate more. I would have preferred a greater variety of challenges, rather than just hiding an ever-increasing number of eggs. I'm not sure how easy it would be to achieve such a questline without splitting it into Ages (for example), but it would be good to have a variety of quests that includes actions such as trading, motivating/polishing a certain number of people, building a new building, completing a research, conquering a province, etc.
From the point of view of collecting eggs, again this is very passive; mainly waiting for eggs to be hidden by other people. It would be nice if goods, coins or supplies (probably not all three) could be converted into eggs so that we could do a bit more active egg-making.
Other than that, I have enjoyed the Easter Event so far.