OK, i have over 30 years riding experience and i'm definitely NOT a big human, i'm about 5'3" and weight about 70kg.
I can say with absolute certainty that there has not been one bike i've ever owned that was satisfactory with the std suspension, and i'm a lightweight! you sir, will have trouble with ANY bike so make sure you factor in the cost to tune it to suit your size. As a new rider i had no idea how to know whether my suspension was right or not, and as i progressed onto better bikes the suspension improved but once i spent money on setting up a bike properly the penny dropped, nothing flashy like a carbon end can etc. but money well spent and my confidence, and therefore my riding improved dramatically.
Don't assume because it say's Öhlins it's automatically better, just because it's branded Öhlins doesn't mean it's any better or worse than anything else fitted from the factory, sure, it's posh, and a well respected name but there is a lot of difference between their aftermarket stuff and their genuine fitment stuff, that's because just like anyone else they have to bid to win the supply contract, so it will always come down to cost. Some genuine Öhlins is genuinely awful, S4RS front forks come to mind, my 1098R forks were so bad i gave up on them and installed Öhlins R/T's built for my weight, riding style etc.
Your size will have a significant effect on what springs you will need, and because of the load the bike has to carry, (You), the damping circuits will need to be tuned to suit as well, don't skimp and just put heavier springs in it, that will help but while you're most of the way into the job do it properly, the result will make your riding experience so much more pleasant, and safer.
I have a Gen1 and i love it, yet to try a 1260, my std suspension was rather awful, too soft in the rear, too hard up front, like every other Diavel apparently and while i tolerated the front for a while after adding a custom specced Öhlins rear once the front was sorted it was a totally different bike, i couldn't be happier.
Good luck mate!