For me, the problem with locks is their weight, what to do with them when you ride, and having to lean your bike up against objects that will scratch the finish. I have a nice bike (I have an old one, also, but prefer to ride the nice one).

Luckily, most of my riding rarely requires me to lock the bike up. During the day, it goes into the closet in my office. At night, it goes inside.

If I stop by a grocery store, I take it inside with me (I've never been bothered about this). Once, at a Wal Mart, the guy watching the door agreed to keep an eye on it for me.

I do need to get a small cable lock for quick errands that require me to briefly lock it outside.

I have heavier cable locks that I use when I put the bike on my trunk rack (I use a Hunch Rack that doesn't have its own locks - my hitch rack locks, and, when I use it I also use a cable to lock the wheels).

If I had to use my bike in a place like NYC and leave it outside during the day, I guess I'd get some beater and a heavy lock (you see them all the time in NYC).

In reality, it is true that, if someone is determined (or in the business to) steal your stuff, there isn't much you can do. My daughter has had her passenger window smashed on her car in NYC twice in less than a year. She uses one of those pedal locking devices, so the perp(s) didn't get the car, and she leaves no valuables inside.

As for my bike, I try to plan my rides so that I have no need for a lock. Obviously, many of us cannot do that. I yearn for the day when someone comes out with a reasonably effective locking system that doesn't weigh a ton, doesn't scratch up your bike, and can be carried easily. For me, that day has not yet arrived.

Caruso