I have dual pane windows and had several that developed moisture between the panes. I had all of them repaired in Hudson, FL 11 months ago. Since I had several to do and 500 miles to travel to get to the repair location I just had all of them done. The repair company warranty is much better than a new window warranty and a the cost is much less as well.
No one above has mentioned the reduction and in my case elimination of window condensation with dual pane windows. I full time and condensation has never happened to me.