Just some update, the issue was fixed after about one month...it's much better now indeed. thanks for this wonderful forum and those ppl who post these useful info!
not so lucky in Canada. The Toronto dealer just told me the US Bulletin does not apply here. They admit the vibration is there but that's NORMAL. They asked me to call MAZDA Canada for more info, called MAZDA Canada and was told they will investigate with dealer and the guy also mention the US...