I disagree.
Disco effect is created by the lenses....which can easily be changed out or ordered specifically to avoid this.
LED's are made by 3 or 4 companies....people over estimate the differences between them a lot. There are more and more LED color choices available now that weren't a few years ago. People also like to put price with quality. I think too many items are over priced in our hobby.
If you go and buy the over priced and expensive LED options out there it isn't worth it for larger tanks. But there are plenty of less expensive options like I suggested earlier that would work fine and save you $$$ on larger tanks.
Just for the sake of newbs that might be reading this:
The "disco effect" isn't fundamentally caused by the lenses in front of diodes. It's caused by the fact that diodes are essentially point light sources, and most (except for Kessil) LED fixtures use separate, discrete diodes of different colors. The refractive front caused by waves on the tank's water surface will generate a color separation because of these differently-colored, space-separated point sources. It will be less noticeable if the diodes aren't sharply focused (i.e., "lensless"), but its still there.
While it is true that all LEDs are manufactured by 3 or 4 companies, then put into fixtures by dozens of companies, there are fundamental restrictions on spectrum because of the physics of LEDs themselves. Specifically, all primary color LEDs generate light in a certain, narrow spectrum, and all spectrums within the visible, UV and IR ranges aren't readily available. Re-emission LEDs, such as cool white and warm white diodes, spread these narrow spectrums somewhat because they use the light emitted by the diode juction to excite phosphors, which re-emit the light on a broader spectrum than the stimulating radiation. Nevertheless, however, white and warm white diodes have a much, much more restricted spectrum than incandescent/fluorescent/metal halide sources.
Finally, while the situation is improving, inexpensive fixtures typically eschew the "ends" of the visible spectrum to keep costs down - this especially true in the near-UV spectral range. More expensive fixtures address this spectral range (410 nM and less) better than the inexpensive ones, but their radiometric output in this range is still quite poor compred to your average metal halide. This may, or may not be, the source of color-shifting and poor health of certain acropora species, which has been widely observed by the community, including experts like Sanjay Joshi.
In conclusion, and keep in mind this is coming from someone with a scientific background that's an LED user - it's incorrect to state that LED fixtures, even high-end ones, produce the same quality of light that is present in the traditional metal halide, metal-halide fluroescent and fluorescent set-ups that have been used in the past. And it's not just an issue of intensity calibration and getting enough fixtures to cover the tank's area and reduce shadowing.
It's unclear whether diode manufacturers and tank fixture manufacturers will be able to address these issues in the future, but many of us that are LED fans hope so.