We like our 42' MH and I agree with Dennis that more states should post roads that are not considered safe.
In addition longer rigs require more consideration in turns that are restricted. I have no hesitation about using 1.5+ lanes for a turn if that is what is required. There are turns that I can make with the front end (before wheels) going over a curb and there are turns where that is not possible.
40+ feet does restrict available parks/sites. Especially older parks including state and federal parks.
Another restriction is that 50A is required for ACs when it's hot at least for us.
But the good news is that in the last 10 years many more parks have longer sites and 50A.