I would hope embarrassment doesn't stop someone from posting their experiences - It could save someone from wasting a lot of money.

I think LEDs have a lot of potential for smaller spaces because of their low profile and the fact they do not require a ballast to drive them (which can generate a lot of excess heat on its own). Also, LED's don't have the same degree RF interference which may be beneficial in some situations.

As stated earlier, HID lights do generate a lot of IR which is not used in photosynthesis and translates to heat. They also generate a lot of green and yellow light which is simply reflected back by the plant pigments. According to data gathered from LI-COR Quantom meter and sensors, HPS bulbs emmitt 2/3 to 4/5 of unusable light/heat energy.