Is a PCV Oil Catch can necessary on LS engines?

[GeoffP]

I have noticed several people have installed catch cans in the PCV circuit on their LS engine. How necessary are these? I understand the purpose but don't want or need the expense if it's going to save me a bottle of oil every oil change. $80-100 is steep compared to a $6-7 qt bottle of Mobile 1. It takes a LOT of oil to pay for that expense.