It works fine for me. I have four of them, and they work flawlessly off both the PACLED64 and the I-PAC Ultimate. (I have both in my cabinet.)
Interesting. I thought these devices were limited to 20ma output current? I'm guessing they light, but not at anywhere near the brightness they are capable of.
Try giving them straight 5v from a pc power supply and check the difference.
*shrug* Its bright enough I have to run them at less than 100%. I want to light them up when the system is running something that takes coins (like MAME). I'm not lighting up the room. I'd say they're brighter at 100% than the Ultralux RGB buttons are at 100%, but probably not by a lot. Definitely not dimmer.
I guess if you have a need to light them up as bright as possible and don't want them under computer control, then maybe its not sufficient, but its hard to imagine any use case where they're not plenty bright.