When you say it feels lethargic past 60mph - is this based on driving a 2014 JGC EcoDiesel? That's certainly not how I would describe it. My other vehicles are a 450hp TransAm and an SV650 motorcycle, so I have an idea of what performance feels like. And while you certainly can't compare a 5000+ pound SUV with my 3,000 pound TransAm or my 380 pound moto, I most definitely did not feel the power lacking in the 60mph to <mph deleted due to a public forum> range.
It does matter which mode you're in, with eco mode being the least responsive. But even in eco mode it feels sufficient to me for normal use. And in sport mode it's quite a kick.