My son & daughter-in-law gave me their pitcher and I have been using for over a year now... 
first off I keep record of when the filter is put in and where I live it lasts between 2 to 3 months before we read the 006.  I use for drinking, my coffee pot, some cooking and my iron.
The new iron has a feature to trap any build up you usually get..... its been 6 months now and I use my iron a lot ....Seamstress... and I have to iron my sheets now ... old, thin skin.... there is NO build up in this iron..... coffee pot the same ... 
I highly recommend any of these containers ... but use these filters....