I won't comment on other companies tunes, there are great ones out there.
I can only go on our past achievements and inform you that we have had 0 issues with our tunes on consumer's car. We have some of the best tuners in the industry (claimed by many, but we work with Ford Motor Company and SCT to achieve optimal results).
We write our tunes specifically to your car, we don't just send out a "standard" tune to our V6 owners or our 5.0 owners. We ask you for all of your information and base our tune off of your set up.
Currently at the shop we own a 2013 Boss LS and a 2013 GT that we do all of our testing on. We aren't the type of company that uses other peoples' cars to do the ole try and see how it works test. At times we will ask members to give us their feedback but we test on our vehicles to make sure they are perfect for the customer.
We also have Cam Idle tunes that have been very successful. Here is a link to a site that shows what others are saying.
Steeda is Officially Taking Orders on the Cam Idle Tunes - Page 7 - The Mustang Source - Ford Mustang Forums
I can go on and on, but I think the customer's testimonials on the forums and the web can tell the story.