Does anyone have experience with healthcare for a newborn/through the first year of life on a high deductible insurance plan?

I'm due next week and we have the option of putting the baby on my plan (a standard PPO with copays and very good coverage) or SO's high deductible plan. Basically, cost of adding the baby to my plan is about equal to our potential exposure under the high deductible plan, so we're really wondering about whether the "gamble" on the high deductible plan is worth it. I understand that vaccinations and well visits are covered, so we'd really be looking at a potential big hit if we ended up in the ER or had some kind of serious condition, but would ultimately not be out of pocket more than we are guaranteed to pay by putting her on the PPO.

Anyone have any thoughts or experience with cost of care on one of these plans in the first year?