If I weigh out the pros and cons of it. I look at the cost, quality and effort (my time). New Yeast
It's about $3/pk. cheap.
Virtually guarenteed to be viable - Pro
Almost no effort (sprinkle over wort) - Provs.Yeast Cake
Costs nothing - Pro
Health and Viability (OK if properly processed) - Pro ?
Effort required to harvest and properly store - Con
AFAIAC - it's hands down. Spend the $3 and RDWHAHB