We have an HMO and I could not be happier. I'm not sure what the choices would be like for your plan, but ours includes nearly every major hospital/medical group imaginable. I knew that I could still go to the doctors I wanted to with my HMO, so a PPO was a complete and total waste of financial resources for our family. I use doctors primarily in the Rush Medical Group (there are tons), while my son is part of the Advocate Medical Group, and I used to be a part of the UIC or related group. Combine the three of those groups and there are tons of doctors, primary care physicians, womens health primary care physicians, and specialists...and I've only named THREE medical groups (ours includes several).
For my current pregnancy, I have paid one $20 copay yet have to go every other week due to a high risk pregnancy. This pregnancy has also necessitated me getting a cerclage - also known as an $18,000+ procedure (fully covered by insurance). With my last pregnancy, it was the same situation (bi-weekly then weekly visits and had a cerclage with that one too) but when it came to my labor & delivery and postpartum care (I was in a private room too) I exceeded my limit. I got a bill for a whopping $124, so not bad at all! Prior to becoming pregnant over 2 years ago, I did 3 years of fertility treatments - all of it was covered except for a copay each visit. My drugs, supplies, IUI attempts, bloodwork were all covered by the HMO; I paid nothing out of pocket. Had we decided to go the IVF route we would have gotten 6 attempts at successful implantation for the first pregnancy and then 4 attempts for each subsequent pregnancy.
I've been pretty fortunate that all of the doctors I've selected within my HMO are caring, dedicated, educated, and reasonable professionals. None of them have been money-grubbing ogres like people have suggested. And...there are many doctors out there who accept HMO, PPO, private, and self-pay plans, not just one exclusive type of insurance, so it's not like they change their attitude from patient to patient (my husband switched from a PPO to an HMO and the quality of service never declined).
And wow, some of the people here must have had horrible HMOs! Whenever I need a referral I basically just ask my doctor for a referral to someone in network and he writes it, no problem.
You should be able to find out ahead of time what doctors might be a part of the HMO plan. From there you can plan accordingly. I don't think I would ever use a PPO, mostly because no one in our family has really unique and complicated medical needs. Then again, each employer has different levels of coverage and payment so it would be best to do your research and decide which would be best for your family in the long run.