2012 USA spec 470hp xj supercharged. Is it better to go with one of the established tunes or get a custom dyno tune by a tuning shop. I will also be getting the lower crank pulley.

 

2016 XJL 5.0 SC.
I have no experience with a custom tune, but what I can tell you is, the VAP tune with lower pulley set up made my car scary - SCARY - fast. At the price VAP charged, I can't imagine a custom tune would give you even close to the HP/$ than the package from VAP can. And it was so easy, convenient and the guys at VAP are top notch.
I'm not saying a custom tune may not be better, but I can guarantee you'll be happy with the results you'll get from VAP.
My $.02.

 

I have the lower pulley and tune from VAP on my 2014 XJR. Very happy and zero problems!
Biggest surprise was the nice increase in gas mileage even when driving the car hard.

Also if you want to you can data log. Send the logs into VAP and have your tune adjusted?
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