hello  to  all 
 i  currentlly  run  on  the  2.5" calmini  lift , the ride is very  nice  .
 recently  i  was  thinking  of     those CALMINI ADJUSTABLE REAR TRAILING ARMS  sk198002,
i  want  to  understand  the  importance  of adding  this  part  to  the exsisting  lift
  what  will  i  gane   by  having  those  arms ?
 do  some  one  have  better  solution ?

I installed the arms with the 2.5" lift. The arms allow you to adjust the drive shaft angle to compensate for the lift. I did notice some vibration after I installed the lift and adjusting the arms did reduce it. I believe the shop that did the alignment also adjusted the arms to fine tune the alignment.

I found the ride with the lift very harsh but they do advertise it as a heavy duty spring.

Busted Knuckle  thanks, but  this  wasn't    the answer  i  axpected   .....
  no  vibes  here
  i'm  more  interested in understanding  the  upgrade   that  is achived  buy  those  arms.....

someone  more?

The upgrade is to be able to adjust your drive shaft angle to iliminate drive line vibrations and prevent u joint failure. At least thats what I get out of it. Every vehicle  reacts different to lifts. I have some decent vibes with my spacer lift.