Re: Beware of seemingly low-cost gifts
Another related issue with stage lighting, even the better units, is the amount they leak to earth. I'm no expert on the electrical design of LED dimmers (it's PWM and black magic) but it seems the most common way to design them involves dumping a lot of noise to earth. This in turn plays merry hell with RCD's - it looks to them like current leakage and they trip. Fine if you're supplying your own distribution, or have a guy like Elmer Phuds friend who can make arrangements for you, but when you show up at a hotel \ conference centre with everything on 30ma trips it can provide an extra problem to worry about.
Whilst we're at it, a more lighting designer rant: only the very best units provide decent colour rendering and skin tones - cheapy RGB units look horrid as front light, but still seem to turn up there, when cheap traditional halogens would do a far better job.