The two times of the year when I lose power are during ice storms, and Spring Thunder Storms. It's hit or miss if it happens, and most of the time, power is back on fairly quickly. For 99% of the time, my little Honda generator is all we need to keep the lights on, watch TV and charge our cell phones.
Since the power loss is so unpredictable, I would have to disconnect what's on my tractor to hook up a PTO Generator. I hate removing what I have already hooked up to my tractor because that's what I'm needing on it. I would hate it even more if I did this before a storm and we didn't lose power, or if I waited and I had to do it out in the weather during a thunder storm. I can't think of a good time to hook up a PTO Generator.
The little Honda cost a grand, it starts every time, it's easy to bring out to where I'm working and have electricity for my tools without using a tractor that might be needed for something else.
If I was to buy a bigger generator, it would be a Natural Gas generator that would be mounted in my garage. Last year we lost power for 5 days from a snow storm. The Honda and wood stove kept us comfortable, but it would have been more comfortable with more power. Not a priority, but something to plan for down the road if a deal comes along, or our power supply continues to fall apart.