If you like extensive teaching, you will love postpartum. Your med/surg experience will only help you. Good assessment skills are very important. People think it is easy or boring, but I find it a lot of fun and not at all easy. Yes, your pt population will be healthier in general, but the complications are horribly tragic (hemorrhage, PE). Luckily, they are few and far between depending on your hospital.
In CA, our ratio is 1 nurse to 4 couplets (baby and mom together). If the pts are high acuity (mag drip), you will have less. Some moms have babies in the NICU so are singles. Also, there are admits all times of day--even at 2am. In my experience working and now teaching, you may have 4 couplets at the beginning of the shift and discharge most of them before 3pm. You are crazy busy at times and slow at others.
You will need to become familiar with newborns, but that can be done. They are so wonderful and helping a new family get to know each other is very rewarding over all. There are down sides, but I think you sounded like a good candidate. Good luck--don't be afraid to change!