We purchased ours 3 years ago so it was 4 years old when we got it.
It was GM certified and one owner with about 45,000 miles.
We've put on about 40,000 miles.
it has been mostly trouble free except for the rear air suspension failed early on.
This was covered under the GM Certified warranty so that was a relief.
Performance and power is decent with the standard 5.3L V-8.
One other problem was excess oil consumption, which was due to a faulty valve cover design.
This was replaced at our expense by the local GM dealer.
Options and space with seating for 7.
V-8 power is great for a vehicle this size and weight.
No improvement suggestions as the Envoy has been discontinued.
unfortunately, the mid-size full frame truck based SUV segment has been eliminated by GM in favor of the car based "cross overs" like the Acadia.