The biggest reason to not use the cultures that have been fermented above 1.060 is those yeast have been put through a more stressful ferment overall. More sugar to begin with, more alcohol to deal with later in the ferment. So these stressed yeast tent to throw out more off flavors.
Well I guess I am still a new brewer compared to many. i've been brewing the last 18 months and about 20 batches under my belt. I'm doing all-grain now. And still working out the kinks in it. I would like to get my process down better to get more consistant beer. I'm into the gadgets. a stir...