Try fixing one and see what ya think.

Old windows are made from old growth wood, glass, and putty. Simple materials you can still get to execute good repairs. If there is rot that can be addressed with epoxy. They could live another century with minor repairs. You could also add storm windows for more energy efficiency.

New windows definitely won't look as good as those. They have a classic beauty that new windows can't replicate due to the insulated glass unit shallowing the depth of the SDL bars on the glass. Reminds me of many homes here in the Memorial area of Houston.

If you're not motivated by more efficient windows or operability, I'd keep them. You might get a handyman to see if he can at least get one window in each bedroom unstuck so that you could get out in case of a fire.

Good advice above. At the end of the day, there are valid reason to repair/restore your old windows, and also valid reasons to replace. Your goals for the project should be the determining factor on which option is better for you.

Toss out the opinion of the window salesman that says they MUST be replaced, as well as that of the old-timey "craftsman" with his overalls and waxed mustache that gives you a line of bs about how you can make the old windows just as energy efficient.

Things to consider:

- Energy efficiency/comfort

- Ease of use

- Maintenance

- Character

- Overall aesthetics

- Cost

- Resale -- including what potential buyers of your type of home in your area may value more (ie: character and charm vs efficiency and less maintenance)