I think you guys have both summed it up well... In my case I was able to use a dual tuner, dual antenna setup in an HTPC to reliably get both American and Canadian stations.
For the amount of TV my girlfriend and I watch, that was more than enough to go OTA only for 3 years or so. The cost savings was substantial and the learning curve, installation, tuning, etc. was interesting to learn about.
Since moving to Calgary, there are only 5 or so reliable HDTV stations, and that wouldn't be enough to pass the threshold of acceptable in our case. So we bit the bullet and subscribed to TV again.
Do I miss OTA? Yeah! I can't stand getting a cable bill every month. And I can't stand having to use proprietary DVR boxes with limited hard drive size. I had 2.5 TB of space in my HTPC and could watch it on any TV in my house, plus was able to schedule and watch recordings through a program called Remote Potato anywhere in the world. I got NFL games without sim-subbed ads too...
Do I like having cable/fibre optic back? Yeah! I get F1 without having to go to a friends house or a bar. I get Rad X, the discovery channel, etc. which I missed before.
So yeah it's a decision that has to be weighed either way, and both options have their pros and cons.