I vote indoors, too.
I've never had a good experience with having cats outdoors. My very first cat as a little girl was an indoor cat...my mom had always lived on farms in Wisconsin and never had an indoor cat before/didn't know what a pain they would be in heat. (Neither of us have ever made THAT mistake again!) After a solid week of meowing and hanging on the screen door, she managed to dart outside. She showed back at our front door poisoned and did not make it through the night. Another inside cat once darted outside...we later found out that she had fallen into a neighbor's neglected, half-empty pool and been unable to get out. For years, my mother fed a stray cat outside. Things went well for at least ten years until new people moved in with a doberman that wasn't fond of smaller animals and could jump their 5' fence... We know that the dog attacked her at least once as she scrambled up a tree and required 21 stitches. After that my mom tried to keep her indoors, but she was so used to being outside that she wouldn't stand for it. A week after her return to the outdoors the dog was seen running loose again and the cat was never seen again. It's our belief that the dog finally got her, but since after the first time the people were told that they'd be fined if the dog actually killed an animal, we're guessing that the jerk that owned the dog found Rainbow's body and disposed of it.
And this was a fully clawed, very street-smart cat. We had yet another stray show up in mom's yard poisoned. A friend has seen people swerve out of their way to hit cats on the side of the road. I've heard lots of stories about pellet gun wounds.
When they're outside you can't control where they go or whom they encounter and once you've taught them to go outside, it's hard to keep them in. So even if things are great now, you never know who is going to move in later on down the road or what could happen if the neighbors kids get a little older and receive a pellet gun for Christmas...