I just analyzed three different plans available to us and decided to stay with the HSA/HDHP. It is an especially good deal if you are healthy and just need preventive care. Preventive care services, including lots of great services for children (which includes and expanded vision benefit under the ACA), are covered 100%. It's quite possible that with no extraordinary issues all you would pay annually is your premiums under an HDHP.
Here's the list of preventive services required to be paid at 100%:
https://www.healthcare.gov/coverage/preventive-care-benefits/It's hard to comment with just generalities, but I compared the plans side-by-side as follows:
Annual Employee Premium Costs
Less: Employer Contributions to HSA
Plus: Deductible
Plus: Medical Co-Insurance Out of Pocket Maximum
Equals: Worst Case Scenario Total Costs
Keep in mind that most of us won't even come close to realizing the worst case scenario and that in your case because most of your care is preventive you may not have much beyond your premiums. And typically, you save alot on premium in the HSA versus the PPO. (If not, the PPO may help you sleep better at night.) As you move from top to bottom of this formula the risks change. You are 100% guaranteed to pay any premiums (offset by employer HSA contributions) but as you pass through the gates to satisfy different expense "buckets" -- the odds are less likely.
Make sure you find out if the deductible is included in the out-of-pocket maximum. On my plan these are completely separate buckets. Sometimes they are combined. Also, be aware of what your co-insurance percentages are for your medical coinsurance out of pocket maximum. On my plan, outpatient surgery is covered 100% (and many surgeries are outpatient these days).
Just do the math... but it sounds like on the face of it you will come out further ahead with the HDHP. Read up on the benefits of HSAs, which are great retirement savings vehicles. I won't comment further as there are entire threads on it all over this forum.