You may already know this but just in case...
LED/SMD lights are polarity sensitive but incandescent bulbs are not. When you install the LED lights/bulbs into existing fixtures, you may find that some do not work. This is usually due to the fixture being wired backwards. Easily fixed by switching the wires around (correcting the polarity).
Edit: Oh.. sorry. You said they have LED lights now so this should not be an issue. Back into my hole....