Local noise has been a concern...but, likely is a minor issue, as they are not normally located near houses. I suspect the impact on birds is small (but, may vary by location) ?   Whether they are attractive or not, likely depends on the location, number and personal views. The location of transmission lines has been an issue (i.e. western PEI, Canada), as some folks have had concerns about health impacts (likely not proven by science... yet, that is).