Mast plug

Hi,
i have noticed recently, that some new masts (gun, prolimit...) do not have a plug that prevents water from entering teh mast, whereas some masts still have it.
What are your experiences with masts with or without plug?
Does water drain from the mast quick enough not to disturb waterstart and other mamoeure where additional weight in the mast might bother you.

Rgds,

G