We did Lemosho to Western Breach, camping in the crater the night before summitting. Total of 7 days, but I'd recommend an extra day at Lava Tower or Arrow Glacier for acclimatizing. The Western Breach was beautiful and not scary at all. I would definitely recommend hearty trek poles to aid on some of slippery snow/rock sections, but ice axe and crampons are overkill for this.
My wife and I climbed the breach in March 2011. This route allowed us to camp in and explore the crater. The breach climb itself was a very enjoyable scramble and exploring the crater was incredible. The next morning we had a short 1 hour climb to the summit.