It’s sort of fine and it’s sort of hell.
It’s not technical (though it can be bloody slippery) it’s not particularly bumpy and it’s not particularly difficult to navigate (though I’ve only done the western half and back)
What it is is absolutely bloody relentless and very long. Start slow and have strategies for overcoming despair. Ensure you are comfortable on your bike for loong periods of time.
I cried when I did it – utter exhaustion, a slightly too long position that became apparent after about 9hours and worry over a tubeless slow puncture – at that level of exhaustion the tiniest thing is enough to tip you over the edge.
I’m hoping to do a double with an overnight stay next summer.