Yeast Harvesting Question

I've just recently gotten into the microbiological world of yeast starters and harvesting. Methods for making starters seem easy enough and I have not had any problems, but I've heard of various ways to harvest yeast. Initially, my gut instinct told me to up the cell count with a starter, and just partition that starter, most to pitch into a medium grav. beer, and then the remainder to store away in some already prepared DME media. But, to my surprise, the guys at my local homebrew shop suggested that I collect trub from the bottom of fermenter and wash.
My question is this: What are the pros/cons of partitioning a starter in this fashion? My biggest concern here is time;I would much rather pitch yeast cultured from the original starter than have to wait weeks to find out if I contaminated the last batch.

I do both ways, though it's determined by the status of my stirplate at brewtime. Washing works, but you don't get as pure of a sample as with a harvest. You can also ensure that the harvested yeasties are full of nutrients, and will store well. Moreover, they're not "stressed" after having done a fermentation.

Washing gives you a much higher yield though, so that's very nice. Plus the quantity of cells that you obtain after washing dwarfs that of a harvest. Either way, you're pitching them both into a new starter for the next batch, right?

If you want to go really microbiologist on them, then you'll need to plate some samples, but for the most part this is overkill unless you're planning on some long-term storage, and your needs necessitate genetically identical yeast.

Cheers