Historically, although the name's the same, Grand Cherokees seem to have far more issues than do the Wrangler line of vehicles.
You might want to look into http://www.jeepproblems.com and other websites to check frequency of repair history and common complainants & issues.
PLEASE bear in mind this is looking at hundreds of thousands of vehicles, and not just one poster's particular JGC that may or may not have been the best thing since sliced bread.
Although I have to connection to the vehicle, pro or con, decades of experience in the industry have taught me to look at the big picture, and not just Uncle Fred's 2015 model which he loves more than his wife.
Best of luck to you. Happy travels.
