freezing yeast: old vs new

After reading the awesome article about freezing yeast on the home page, i was planning to try it. my question is are yeast that have been used to brew as viable as just making a yeast starter and using that instead? I have read if yeast is stressed in a brew they will produce off flavors if you re-use them is this true? can i make a starter on a brew day and just freeze part of that before i pitch? if i do that should i just make a larger starter?

I had this book in front of me... From Chris Whites "Yeast"

I've frozen plenty. I do it the super scientific way. Wash yeast, pour into mason jar, place in freezer. I make a starter using about 2x the amount I should to account for loss. The dead yeast should be a nice nutrient. I use a mason jars worth of wort from my previous brew as a starter. That too is frozen then thawed.
I haven't had any complaints with this process, but can't give you hard numbers or the science.

There is conjecture, which is infinite on this site, which I love dearly, or there is scientific research from the best in the field I was honestly pissed that it took me five years of brewing before reading this book!

It's on the long list.

I hear ya got tired of guessing though