Caketastrophe
2012 - 7 days, no F2P box
2013 - 14 days, 25 tokens for box
--Free Elevators--
2014 - 8 days, 60 tokens for box
2015 - 7 days, 60 tokens for box [was 65 when event started, but went back to 60 a couple hours later]
Dark Harvest Festival
2011 - 14 days, 25 token for box
2012 - 16 days, 25 token for box
--Free Elevators--
2013 - 13 days, 25 token for box
2014 - 12 days, 25 token for box
Winterfest
2011 - 29 days, no F2P box
2012 - 23 days, 400 token box
--Free Elevators--
2013 - 23 days, 400 token box
2014 - 17 days, 400 token box
There appears to be a pattern of making the F2P rewards increasingly difficult to obtain during the event.
To some extent I actually agree with the changes. Players tend to get tired of events rather quickly, and constantly throwing new events or content at them is a good way to get their attention back. Items like the caps are also immensely common, and would feel much more special if made a bit harder to attain.
The big thing that I don't like is the idea of it going too far. These events happen at inopportune times- when I'm busy going to Halloween or with Xmas, for example. Forcing me to choose between going out and having fun vs staying in and grinding is not something the game should be interested in. The black kat event and whisker/book situation is a great example of the game going too far with regards to its F2P goals- I would rather we not have our other events go down that road as well.