My quick rule of thumb: if no-one is dressing up as a character from an IP and touring conventions, but the books are still finding an audience, the readership reaction will be 'oh, that's interesting' or 'meh' as one-and-done responses. Even Stephen King, arguably with a fandom as large as X-Men, doesn't have to deal with fan-think on anything like the same level as your average 10-issue writer does on any Marvel/DC title.