2 free builder potions, no-brainer here
Traps gain a decent 22% growth which is actually just used to counter regular WB. For all normal usage, they are pretty useless. For 12v13, these trap upgrades do nothing.
Hammered my siege barracks to max.
Used my two book of spells to max out my earthquake spell which was the main reason why I wanted to max them in the first place. Month to month, I only consider which books I have available to decide what troops/spells I want to upgrade.
With battle blimps maxed, I can now finally interchange and use all 4 siege machines depending on how my raid goes. This is especially useful in yeti smash attacks to see if you got the TH or not.
Finally, I have started my final building upgrade and with the 2 free builder potions from earlier today, I only need to wait 4 days before they are finally complete and I will be finally maxed. Sweet release!