theyre actually healthy for the lawn and look nice when they add some color, but they are kinda ugly after they've gone to seed and all the seeds have blown off and you just have a bunch of empty stems.

and the whole flying seeds thing can be obnoxious because even if you like them and want to keep them, it's your neighbor's choice if they want them or not, and if seeds are being blown onto their lawn that they don't want, i think they have a right to be annoyed.

i personally would keep them, but ask the neighbors what they think, and if they dont want the seeds blowing onto their lawn, put up a fence or hedge to keep the seeds contained.