For those interested, I got a filco camo tkl with browns. It is working perfectly, no ping no problem at all. It's so good that I got a second filco for the job, same keyboard but ninja version instead of camo, still tkl and browns. This one was a mess. When I started to type on the ninja, I felt something was wrong. It was probably way more obvious because I also have a camo. The problem with my ninja is that ALL the keys ping. It is even way louder on the bigger keys. It is so loud and annoying that I even FEEL it when I type. The feeling aint that strong, but it's enough to remove some of the pleasure and precision that I can feel on my camo.
I also felt a difference when typing with the ninja VS the camo. I have the feeling that the camo has "thicker" keycaps and so feels more sturdy. But it could be an impression caused by the pings/vibration problem on my ninja. If someone else used both a camo and ninja version with browns, I would like to know if you felt a difference between both when typing.
Anyway it's now on the RMA process. If all goes well, I should be able to get a camo instead. Looks strange in an office, but I kinda get used to this look at home and in fact find it nice. Anyway, #1 criteria for a keyboard is the typing experience, the look is quite secondary (even if we all want a badass looking keyboard)