Should i get the SLR Motorsports Performance Chip ?

I have a Scion Xa 2005, and iam thinking of getting the SLR Motorsports Performance Chip and my fiend is also going to get it for his Ford Mustang. Anyone has it or heard of it and can you tell me what you guys think? Here is there link a href="http://slrmotorsports.com/shop/index.php?l=product_detail&p=730" rel="nofollow"http://slrmotorsports.com/shop/index.php…/a