One other note to add to Joe's comments about the old trail: it's not maintained any longer since the "new" trailhead went into play 30-plus years ago, so it's narrower and a little more rugged than than the initial section of the MMWT you would take if you started at the current marked trailhead. It's also a bit steeper. Still, it's better than what you'll see higher up on the MMWT. Personally, I think the trail is in great shape and easy to negotiate, especially to be un-maintained for so many years. I've hiked on much worse that were presumably groomed trails.
As to why I like it, it's all about avoiding that first water crossing of the North Fork. All the other water crossings along the MMWT are tame or very mild. The North Fork crossing is not particularly difficult under good circumstances, just long - but I'm always conscious of that cascading drop-off just a few feet away. A heavy overnight pack + high flow + a little bad luck at the wrong time could result in a bad day. There's still a helluva lotta snow to melt above, so I suspect the North Fork will be running high (at least in the afternoons) for most of the rest of the summer.
