I made the same transition from TriCare last year. It's similar, but with less B.S. No physical required. The company pays all premiums. The co-pays are a little higher than Tri-care Prime. If you are retaining gov't-provided heathcare as a military retiree, then Tricare will pay the difference if the co-pay from your primary insurance is higher.
Aetna has been VERY easy to work with. Under our plan, the list of providers, at least in Dallas, is very large and we don't even require a referral to see a specialist.
You also get to choose if you want to set aside pre-tax dollars for medical expenses each year. It can be used for all kinds of co-pays to dentists, m.d's, eye-exams or even non-presciption meds. This could be a significant tax savings, depending on your family situation.
Overall, no complaints here. I think that says alot for a heathcare plan.
-NTFB