Sorry again to hear about the death of the 3.7.
I wouldn't see this as a complete loss though to be honest.
Here is what I see you are getting....
4 piston front brake setup iirc on the eco pp
3.55 gears - so you lose nothing here
19" wheels all around with new tires. Wheels are pretty cool. I wouldn't swap them out.
A very much upgraded interior vs. your 2014 (I am sure you got excited)
and of course...more torque stock!
I would just stick with light power mods. Don't go overboard.
I am sure you will have more fun with this then you did with your 2014.
I am more of a fan of the IRS then I was the solid axle. The car feels more planted from all 4 corners of the car.
Plus with the new features of the S550, I am sure you will be pleased. The keyfob is a nice touch. So is push start. And also know there is a "secret" button above the license plate on the back so you can open your trunk from the outside
Backup camera being standard is pretty cool also. So you lost nothing with your raxiom gps unit and such.
I am not crazy familiar with the ecoboost but I am sure you will find out more cool stuff with the S550.
I know it was painful to install all of that on the 2014 only for it to be RIPARONI'd. But, take it as a great learning experience. That is what I did. I now know a lot about just basic maintenance and installing stuff now because of my 2014.
If I got an ecoboost, I would probably swap the hood for a GT hood.
My starting mods were...
Oil catch can
And clutch spring - http://www.steeda.com/steeda-s550-mu...-all-555-7022/
In stock form, the clutch pedal felt inconsistent. Once I swapped it out, it made the S550 much easier to deal with.