I was on a white crf450 and my buddy was on a klx300, but we did see two ktm dudes on smokers at the staging area in the morning. Later we came up on a 4-man ktm crew out of truckee.
For this trip we went clockwise just because that gets you to the western states trail faster, otherwise I think I prefer to go counter clockwise, especially in the summer so you're not up on that exposed ridge at the end of the ride trying to get up those crummy rocks. Trail 6 in general would just be an intermediate trail if not for a few sections. If going clockwise, I think the only hard part is the previously mentioned rocky ridge section. If going counter-clockwise, I think the only hard parts are the rocky climb out of the first bridge (which can actually be really easy if you manage to get on top in the middle) and the switchbacks that I think are after the second bridge. On trail 6, I think you can get by with less skill if you simply have good energy and don't mind lifting your bike. It's the beginner/intermediate guys who are beat after 25 miles that will have a bad day, imo.