Lovastatin vs Lipitor

Several years ago my doctor(s) told me to do the following:

Double my dose of Advicor (1000 mg SR Niacin - 20 Mg Lovastatin)
I had been taking 1 per day; went to 2 per day

Take 1000 mg Fish Oil capsules - 2 per day.

My total cholesteral was already within range, my good cholesteral was lower range.

My total and bad cholesteral (& triglycerides) dropped like a rock (100) - My good cholesteral shot up to 70 (best ever)!!!

I can get Lipitor at NO COST and pay for OTC SR Niacin vs copay of $143/3 mo for the Advicor.

My question is:

Does Lipitor work as well as Lovastatin??? Should I switch.