Should you pick Disappointment Cleaver or Emmons Glacier for a Mount Rainier climbing permit?

Pick Disappointment Cleaver for infrastructure and Emmons for solitude; the summit odds are nearly identical. The DC sees about 7,600 attempts a year with a 51% success rate, running through Camp Muir at 10,080 feet, which has huts, an outhouse, and running water in season. The route is maintained through the season, and fixed lines may be present on the Cleaver itself. The costs of that convenience are crowds and rockfall, which is common on the Cleaver in the afternoon and worst late season in warm weather.

The Emmons Glacier route sees about 1,600 attempts a year with a 54% success rate through Camp Schurman at 9,460 feet, where a seasonal ranger station is the only amenity. It is unmaintained, so you do your own route-finding through a heavily crevassed upper glacier, and the approach is longer with about 10,000 feet of total gain versus 9,000 on the DC. Best conditions run June through September.

Either way, plan a 2-to-3-day climb with a summit push starting between midnight and 2am, and treat acclimatization at high camp seriously. Overall the mountain turns back about half of the roughly 10,000 climbers who attempt it each year, mostly for weather and altitude, not technical difficulty. Permit pressure is heavier for Muir weekends, so Emmons dates can also simply be easier to get.