Do pre-apprenticeships help?

Just started a free 16 week pre-apprenticeship in east bay, CA and was wondering if it's a big advantage when come time to apply for 595. I'm wondering if i should go straight to the union apprenticeship with no knowledge and be paid rather than 16 weeks of this program with 0 pay. I know the answer is pretty straight forward. Instructors informed us we'd be getting 7-8 different certifications here as well