Our feedback on using the CoolLED is very positive.  We recently purchased the new microscope with the CoolLED system. We replaced our previous microscope which had a Mercury deuterium lamp. In comparison with the old lamp there are many advantages to the CoolLED system.  The warm-up time is significantly less.  The field remains evenly illuminated even when switching between magnifications and, the system provides an excellent quality of light for taking live photographs of cell cultures.  From a Health and Safety perspective, it is much better to have the cooled system than to have the Mercury Deuterium lamp.  The lifespan of the LED system should also significantly surpass that of the lamp and, as an LED system, the running costs should be lower than the old lamp system.