there is no reason to ever use boots, even mid height on the WCT. Trail runners are the standard nowadays for 98% of backpack trekking, including the WCT. Boots are needed for alpine mountaineering, not these fairly easy park trails.

We wore low cut trail runners, with gore tex and shorty gators on the WCT and many JDF treks (an Sierras, and everywere else). Did not get one soaker any time. Helps keep us spry navigating the gnarl, esp with starting weight pack at 25 lbs.

Boots will tire you out, slow you down and far more likely to cause foot injuries. plus just plain too hot

hiked a 100km trek with a pair of super experienced guides in the Sierras a few years ago. They had 65 lb packs. And, of course, trail runners.

leather boots are like hiking with 40 lb packs - obsolete for most places in 2018. Just ask Andrew Skurka (though he says don't even need to bother with gore tex) who does 5,000+ mile off trail treks.