The one trip where I brought the wrong shoes and paid for it. Worth it anyway.
Just don't skip the recovery day, your knees will file a complaint.
The trailhead is a couple hours from Kandy by shared van, but the trail itself is unmarked in places.
Go with someone who's done it before, or at least download an offline map.
The route I actually followed — adjust the pace to however much rain you're willing to walk through.