So I purchased my new 2016 GLE 450 back in November of 2015. However had originally placed an order since I had to custom build the vehicle from the ground up from the factory. In all honesty the car is great and has an immense amount of power. You can easily get the car tuned as well for less than $1000 through a plug and play chipset. The price gap of 40K between the 450 and 63 isn't worth it in my opinion. Stick with the 450!
So they provide information on how to install it. I'm sure you or a mechanic can install it as well. Well they're claiming that it will add a minimum of 60 more horsepower and torque. Being that it's a chipset your warranty will not be affected since you aren't technically "tuning" your vehicle through the ecu. Therefore any warranty claims can be done. The only thing I would say to do would be remove the chip whenever you're going in for service or god forbid any recalls.
I'll be waiting around for a good number of road test reviews to happen with these, since depending on how that power is distributed it could make the difference i'm looking for or not. Looking forward to what you guys have to report back.