You may think pantylines are great, but they are NOT stylish. It is considered a fashion "faux pas". I would not be caught dead with pantylines in public, I would wear boy cut panties to bed like "pajamas" but not in public under clothes.
If you have panty lines guys might not know that you are wearing fabulous sexy boy cut panties under your clothes, they might think it's "granny underwear". It is a fashion mistake.