Understanding that the factory ESA is a one-size-fits-all compromise, it's a damn good, damn effective compromise. I've got 12,000 miles on my 2012 Adventure on everything from fast mountain roads, to busted-up urban streets, to rutted-up dirt and sand trails. It's done a tremendous job dealing with varying loads and surfaces.
Get it with the bike, and if it fails during the warranty period, it's repaired for nothing. Once the bike's out of warranty and it's on my dime, I'll look into Wilbur's or Ohlins.