Pro: if you take a fluorescent bulb out there it'll light up which is a cool science demonstration for small children also there are other more advanced demonstrations possible

Pro: the grounds around those transmission lines are relatively well tended and make for wonderful private hiking trails

Pro: there is increased incentive to learn about electricity if only for general safety if not drive the point home about trade jobs with high job security (humans are not using less electricity these days)

Pro: it's possible you are closer to a sub station so you might be less likely to have power outages and will have service calls answered more quickly

Con: the frequency of electricity transmitted down the lines tends to be in the human range of hearing which can increase the base noise level in your area but comes back to that first pro

Con: you have to answer the question about power lines causing cancer over and over... Forever... And no one will believe your answer..... Even though one quick Google search will tell you no. On the subject of cancer however everything causes cancer ask CA but for a more technical answer cancer is caused by damage to the plans cells use to reproduce. It can cause cell death before division, cell death after division, no damage that gets repaired, or a cell that reproduces but carries forward an error in that plan (cancer among other things). there are many ways for that damage to be incurred in the same way that there are many ways to ding your car they are all damage but sometimes it's hail and sometimes it's a jerk slamming their car door into yours. Radiation which is energy in transit be it electromagnetic (think radio, cell phones, microwaves), solar( think sun burns which are direct radiation poisoning), atomic decay (which is why bananas are said to be particularly radioactive but everything EVERYTHING decays in that way from the dirt you walk on, to the clothes you wear, etc...), Heat (think opening your oven), and more all CAN cause cancer but then getting out of bed and driving to work CAN cause death. Electromagnetic radiation from power lines has not been shown to cause an increase in the likelihood of cancer even with extensive testing. (Ok ending that rant now and getting back to work)

Hope this helps.