Hi Tenerist
The 660x is a mortard and I have not riden it myself. On the other hand I had both a 660R and a 660Z ( Tenere ). Completely different bikes, the R weigh a lot less and is much more nible.
I really did enjoy my 660 Tenere, I grew into the bike. A lot heavier and higher than the R. I did a full house on it, Power Commander, Leo Vince pipes, Third stage air filter and the HyperPro suspension upgrade. She was producing a nice 42 Kw. I changed the front sprocket to a 14T, my feeling is that should actually be the standard sprocket for the 660z. So much fun! Very capable but a handfull in thick sand.
I am still running in my Super Tenere, only done 900 Km. With the smoothness and all the raw power of the 1200 twin cylinder riding tar is a real pleasure. Have not done much gravel yet, but the bit I did was a real pleasure.
The misses is really impressed, she enjoy the bike as much as I do.
In short the Super Tenere makes me smile every time I ride it.