J, I dont know if it is worth the price or not but I already had my mp8 before my smarty. However on MY truck I run little to know pressure but it is nice that when I do want it I have the dial in the dash for the mp8. The mp8 is much smoother than the tst pressure too, though tst could have refined that since I bought mine.

Its just what I have experience and there is an mp8 in the classifieds.

 

I like the MP-8's adjustibility better...worth the few hundred dollars more if you have it...