These are absolutely horrible. I've bought them before from ebay and every single one of you will probably regret buying these. First of all, they really only work if you have white LEDs to begin with, and even then, they dim the brightness SO MUCH that even with LEDs on max brightness, the colors are incredibly dim. Far, FAR too dim. Not only that, but on keyboards with a numberpad, they almost completely prevent the + and enter keys from operating due to the vertical positioning of the switch bringing the plastic into contact with the inside of the keycap. Now I will say that I do not know with certainty if these are the same brand I got, but I can't image being able to improve upon an unworkable concept. On top of all these problems, there is yet another - if you tilt the keyboard very much at all, they can dislodge EASILY and then you have to remove the keycap and re-seat them. Often. Horrible, horrible product.
JalucianYou must have gotten a bad batch or something, because i have these and they work great. Nothing that you listed above has happened to me yet and i have had them on this board for a long time now.