We walked along the waterfront and up the side of the cliffs. It's a pretty long walk and it's not good for kids or pets (mostly ok, but there are some steep bits and narrow bits). You can get a good view over St Johns (assuming no fog). The only con that we learned - pretty much everywhere in Nfld - very little is open before June, so bathroom facilities or eating facilties at tourist areas are generally closed before June so keep that in mind.
If you own or manage Signal Hill, register now for free tools to enhance your listing, attract new reviews, and respond to reviewers.