Mine got huge slack in chain tension on first 1000 miles. It made big difference in shifting but after adjusting the clutch as per owners manuals, all is good again.
One thing I noticed when I owned '14 model was that at the dealer, the mechanic adjusted the chain slack with me sitting on the bike. It deteriorated the quality of shifting. But after adjusting it as owner's manuals says, 20-30mm with the bike on the side stand, it was as smooth as butter.
One more thing. On first few oil changes I trusted the dealer on type of oil. I've observed what the mechanics were doing. It was the oil from huge barrel and I had no idea of the quality of it. It was good for 1000-1500 miles and then the shifting problems would start. Then, two years ago, I decided to bring my own oil, recommended by Suzuki, fully synthetic and demanded to use that oil. The dealer used it, no problems. With that oil and always correct chain slack, all my shifting problems were gone for good.
Now I own '18 model and the story with the oil is the same. But now my dealer has that exact type of oil on the shelf so I don't have to bring mine anymore. Other owners of DL1000 heard of what I was doing and now they all ask for that oil. I know it's big hit on dealer's pocket, as the oil in huge barrels cost him almost nothing but I don't care, I prefer smooth shifting.
2017 DL1000 White
2014 DL1000 Red (sold)
2012 DL650 White (sold)