Just got my new IRS lower suspension arms in today...man are these things sweet! Even with the IRS pivots the lower pivots are a bit snug but that will work in on it's on. The arms are just a hair thinner where they bolt to the chassis then the AE which is good for me as it gives me a little bit more room with my servo since it runs flat in the Mx2. I always suspected it was just a hair off center and now I can fix that. The arms themselves look very strong and have no tweak at all. Just be carefull which way you insert the pivot balls. Because the arms are universal left to right you end up inserting 1 pivot ball in from the top of the arm and the other in from the bottom of the arm.