Sturgess who are one of the main Jag dealers will always give you a courtesy car for any warranty work apparently, just going on what I have seen on the Jag forums, mine is out of warranty anyway so I wouldn't even get a skateboard
Honestly I looked around for a good while before I got my XFS and yes there are a few niggles, but nothing scary, the engines and drive train are tried and tested, yeah you could get a Friday afternoon car like anyone I guess, but Jag are high on customer satisfaction for a reason. No reason to think the XE will be any different hopefully but nothing is guaranteed