You can talk shit about the KLR650 as much as you want but it is the bike of legends.
It's a fine mule of a motorcycle. Going beyond that is absurd. There are so many other 650 singles that do the same thing just as well. The whole "doohickey" thing and the need to repair it RIGHT OFF THE SHOWROOM FLOOR doesn't sit well with me.
Rabid fans jumping to the defense of any given bike is a pretty good sign that it's a piece of shit that instills a Stockholm syndrome upon it's owners. You needn't look farther than Harley or KTM for similar examples. Both bikes have objective shortcomings, but the fan base will defend them to the end with blind enthusiasm.
I still have fond memories of a KLR owner telling me how superior his bike was to my Buell. Something about the single cylinder being the pinnacle of simplicity and reliability. This conversation happened while we were hooking up a tow strap because his timing chain had failed and I was towing him to pavement. Something something pushrods and gears vs timing chain...
That doesn't mean my Uly is superior. That engine architecture has advantages, but the bike will NEVER be as capable off road as a KLR. A KLR will also never see a sustained 100+ mph on the highway. I will never have to adjust or lube my chain or valves, the KLR will never break a belt. There's no "best" bike. There's no "legend". Get the fuck out of here with that shit. Every bike is good at some things, and useless at others.
Sorry to detail the thread OP. I do hope you sample the 950/990. I'm a fan of that bike with a 17/19" wheelset. They're definitely agile, well suspended, and have a genuinely enjoyable engine. You'll definitely miss the ease of maintenance compared to your GS, but there's no free lunch.