What's the best laboratory booster?

I can never decide which one to use & when until I impulsively choose one (or see a regatta task that associates with it, such as the ingots being made faster).

I LOVE Generous Customer Booster but tend to shy away from using the one with the ships (again unless there is a regatta task I can do). I used to be glued to the game but it's been going downhill for a while, so I often go long(er) periods of time not checking my town & don't want to "waste" it on that one.

I love the one that doubles the harvest but I often run out of room quickly on my barn, so sometimes I feel I can't use it as much as I'd like.

What are your opinions on them?

I can never decide which one to use & when until I impulsively choose one (or see a regatta task that associates with it, such as the ingots being made faster).

I LOVE Generous Customer Booster but tend to shy away from using the one with the ships (again unless there is a regatta task I can do). I used to be glued to the game but it's been going downhill for a while, so I often go long(er) periods of time not checking my town & don't want to "waste" it on that one.

I love the one that doubles the harvest but I often run out of room quickly on my barn, so sometimes I feel I can't use it as much as I'd like.

What are your opinions on them?