M2's units are simply the best and if you can afford it by all means, install one. it's just a dam shame something, the guard diff so freaking pretty has to be hidden away.. really!

I had one put in my spec 911 early on in it's development and "street drove" it for 6-8 months with no significant ill effects. I did not, and continue to not often park my 911 in a parking lot that is full enough to require tight turning radius' so that could be why I never noticed it. really, after installing it having tracked the car for many years with an open diff the biggest change was in braking. you can stand on the brakes at locking threshold and the ass follows the front until you want to purposely rotate the car with greater steering input. with the 230hp at the wheels spec motor I ran it never broke loose on corner exit under power open or LSD diff. even at the tightest of tracks like button willow no rear wheel spin with a open diff, but standing on the brakes in a stable guard equipped car coming into that slow, tight turn is what made better lap times.

if you've got the dough you MUST go, otherwise do the suspension work 1st and see how that helps develop your skill set.

t