Kingofgix I own a 2014 non ES, and also have to count myself among the lucky in that in Tour Mode I do not expedience any of the FBW fueling snatch that is seen across the line, models, and model years in Sport Mode... In Sport Mode my Super Ténéré does hit hard, but I wouldn't quite describe it as the snatch like explosive fueling I've experienced on some other Super Ténéré's I've ridden. I would add my bike does seem to be running a bit rich, at idle and just off idle...
Unfortunately as the Super Ténéré is all CSS and not CAN Bus compliant, it's neither cheap, straight-forward, or easy to resolve fueling issues; like a lot of things on the Super Ténéré when they function properly they do so flawlessly and probably will for the life of the bike (or even the owner), when they don't it's a giant pain in the ass to fix, with more disassembly, and farting around to get things right then the Space Shuttle -- but it can be done.
Whether it's 'worth it' will depend on you and the amount of time, the tools, and money you may have to turn to the task of getting things where you need them to be. No mass produced motorcycle fits every rider out the door and is 'turn-key' ready, all confer additional cost, time and effort to resolve one-size-fits-all but fits none issues, and cost savings issues of mass production. To the Super Ténéré's benefit, it probably does better then most in this regard at lower cost due in part to its low price, success and the enormous after market of parts -- so the net cost to you even with resolving fueling issues may in time and money come in under other bike(s) you may be considering...
In that vein I also like the Stelvio NTX you mentioned; in my opinion it's excellent competition for the would be Super Ténéré customer's attention with similar size, weight, performance, and geometry -- it also does a lot of things well that the Super Ténéré does not (the converse is also true) like maintenance autonomy, range, better stock suspension, better brakes, better ABS and TCT, fewer fueling issues (and cheap and easy to resolve for just the cost of a computer cable should you experience any issues), and the bike vastly easier and cheaper to self service if your time is worth anything...