I agree with Bobbi. We have a Chariot trailer that has gone through 2 kids. My hubby and I ride a lot. We also live in northern CA, so lots of steep decents and climbs. It is good for bringing along toys, snacks, and your child can nap fairly comfortably if they fall asleep (similar to the car seat while driving). After researching, we felt like the trailer was the safest option for us. It only takes a minute to hook up or remove. I would visit several bike shops and see if you can test a few options out, just to see how each thing feels. I also know from experience that if you are dealing with hills (5% grade or more) it will take getting used to pulling the extra weight of the trailer, but I think your child will be safer in that than a rear or front seat. I would think that if you had a bad crash, the front or rear seat would not protect the little one very well. If you crash with the trailer, it is designed to not roll, and the "walls" of the trailer would help protect from road rash. It also seems like the front seat would throw off your center of gravity a bit. It also comes down to how much riding you do and what KIND of riding you do. Strolls around the park are a lot different than a RIDE - up and down hills, several miles, traffic, etc. I have heard of many cyclists who ride with the trailer empty sometimes, just so that cars will give them a wider space when passing (It comes with a big red/orange flag you attach with a post so that you are that much more visible). When cars see that thing, they know to stay away! Good luck in making your decision.