I've owned a DR350, the air-cooler cousin of the DRZ400, and I've owned an XR650L. They are COMPLETLY different to me. The Suzuki will do most things fairly well, the XRL is a MONSTER-tall bike. Both are fairly heavy. Both are tough. If you think you'll be in wide-open spaces off-road, the XRL would be best. If you are going to be on more single-track trails...I'd recommend the DRZ over the XRL.
I sold both of those bikes, and replaced them with a KLX250S, bored out to 331, and with suspension upgrades front and rear. It's paired with a KLR650, which I've kept through all the variations of dual-sport bikes I've owned...it is NOT the best bike at anything, but, it CAN do almost everything.
Have you considered the new Husky TE449? There are some really nice bikes out there. Of course, KTM's deserve a look.
It all depends on how much you want to spend, and what you'll actually be using it for. Good luck with your search and decision!