I would imagine most people that don't like pediatrics, don't like working with children. They most likely don't like the behavior guidance aspect of it and they possibly view the typical treatments as unchallenging. If you enjoy working with children, instant gratification, super busy schedule and a challenge, you will like pediatrics.
Behavior management is a term we are getting a way from. We are now calling it behavior guidance. Some aspects of behavior guidance may come more naturally to some than others, but overall, it's a skill that you will acquire as you complete your residency.
Going to the OR is going to depend heavily on the type of practice you have. If you are working with young, low-income, hispanic children with good medicaid coverage, you're probably going to the OR a lot. If you're working in a "prophy practice," you probably aren't coming any where near an operating room. It will also depend a lot on what you're comfortable with. Some residency programs give you ZERO experience with sedation meds (Demerol, Phenergan, Hydorxyzine, Versed, Chloral Hydrate, Ketamin, etc), so these individuals only feel comfortable going to the OR. Hopefully, in the future these programs will be held accountable for this and start teaching sedation or shut their program down.
I know practitioners going to the OR 3 days/week with 5-8 cases/day while others go twice a month. There are others who have been practicing for 20 years and haven't been to the OR since they were in residency.
Hope this helps!