It was really hard for me near the top. There just wasn't enough air and the path was not particularly smooth. But I'm roadie and not a mountain biker, so that may have contributed.
That said, it was totally worth the effort. Even if you have to push, it's worth it. The views are AMAZING.
If you go, remember to STOP for the views and not just ride off the edge into the air looking at cool stuff.
Also, when I went there were a few spots I had to carry my bike over. Not a huge deal, but easier with help.
Depending on how dry it is, that sand section can be a pain. Again, I'm a roadie, so real mountain bikers may have an easier time. I just plowed a lot.
Still, and I can't say this strongly enough, it's an amazing and wonderful ride. Do it!