Lots of info and users of the DiabloSport tuners here. I'm sure most of what you'll read here is:
1. "Great product"
2. "Gotta update it first before you try to install it."
3. "Get a custom tune done."
4. "Get in touch with Moe's Performance for the best price."
I've used DS products on two HEMI powered vehicles and I found that they certainly were worth the money!
1. They optimize the air/fuel ratio.
2. They move the torque and HP gains down the RPM band and your vehicle will feel a lot more responsive.
3. There are functions you can use to change tire sizes, WOT shift points, throttle response and other settings for rev limiters, speed limiters and data logging.
With a Predator programmer & a custom tune I went from 368 RWHP to 412 RWHP on my 300 SRT8.
Here's the HP/Torque and Air/Fuel ratio dyno curves from my 2007 5.7L MegaCab:
If you need an explanation of what you are reading in those dyno graphs above just PM me.
I'm sold on the DS products and will be adding a programmer to my 2014 6.4L powered truck soon.