Looks like the options are:
KTM Adventure
Old 1100/1150/1200 GS of some sort
KLR650
. . .
I really like that there is a good variation between the 650 all the way to 1200 but they are similar bikes.
Those are all VERY different bikes! Sure, they are all loosely referred to as 'dual sport' bikes, but you just can't really compare a KLR with a KTM ADV, or a big GS. Heck, you really can't compare a big GS with a big KTM, about the only things in common are the number of wheels, and the HP that the stock engine produces. Outside of that, they are very different machines, each one outperforming the other in different ways.
One thing about this 1200GS (though it may have needed a tune up) but it really didn't feel "1200 powerful" at all, in fact it felt like a strong 650 to me. And the KLR650 for example seems pretty powerful as well...
The KLR puts out around 36hp, the big GS about 100hp. If the 1200 felt like a 650, it needs more than a tune up.:Wow1:
The big thing for me is I want the larger dirt bike feel and the problem is I am 6'5 with long legs (37" technical inseam, wearing a 34" inseam pant) and find most bikes too small. So that also changes things a little.
BMW tends to cater to shorter riders (hell, I can reach the ground on a 1200GS -- so you *know* they like short guys!). KTM doesn't really give a rats back end about us short guys. Put me on a 950ADV and both my feet dangle in the air. That's not a problem when moving, but coming to a stop creates some challenges.
It's all about what fits you (physically, and mentally).
First, figure out what kind of riding you want to do on *this* bike (and realize that there is no 'do it all' bike out there -- some try, but they all fail). Are you looking for something to go poke around the back roads at low speeds? Are you looking for a bike to ride hundreds, or thousands, of mile up and down the freeway to remote areas to explore? Are you looking for a bike to ride tight single track with? Are you looking for a bike to explore the wide open desert with? Are you looking for a bike to live off of for extended periods (RTW travel)? Each of these will favor a slightly different bike. Sure, some overlap, but you are always giving up *something* -- so decide early on what you want *this* bike to excel at (you can always add more bikes later as your needs, desires, and riding style change) -- and they WILL change).
Use that decision to narrow down the list of potential bikes, then see which of those physically fits you (keeping in mind that it is easy to change bars, pegs, etc to tweak the ergonomics).