Hello, Community. I have sound double-hung windows with single panes and want to move up to more energy-efficient glazing. I was asking around about replacement sashes (sashes only, with vinyl jamb liners - not full "pocket window" inserts), as the lowest-cost upgrade, as well as one that won't change the character of the windows so much, but the "window guys" I approached warned me that replacement sashes leak air and noise. They recommended prime window replacement, which of course is way more expensive. So my question is this: if replacement sashes are correctly measured and installed, do they still have to be leaky? Thanks!