100% P&T - VA vs Private Healthcare

Spouse received 100% P&T last month after getting out of the Navy. He just started a new job (for a major hospital) with excellent healthcare - he has to have the healthcare policy so the kids and I have coverage.

Should he go to the VA for healthcare or just use his private insurance for civilian healthcare. What are the benefits/negatives of both?

Can he still get his medications covered through Express Scripts without going to the VA?

Why is it so hard to find information about this?