Aside from the time/effort spent, manual washing also uses 5x more water on average than a dishwasher. And I'd rather not clean the rest of my house with dirty dish water.
What kind of pre-wash routine is factored into that 5x number? I completely buy it if you just chuck the dirty dishes into the dish washer, but in my experience getting good results from a machine requires pretty extensive rinsing at the very least.
