well... if a characters not interesting theyre hardly a strong personality. so we can take that as a given.
personally, id stick around through a slow start for good characters and the promise of a good story. like if what i know youre plots gonna be excites me, ill wait for it.
however, i would recommend trying to avoid slow starts as much as possible (i say this from experience bc im. always. starting slow) because it makes the standard required for your writing, plot, characters, and art (especially) that much higher. usually beginning are slow bc of exposition and introducing characters - so look back at what youve got and consider how much the reader needs to know to start. for characters: name, face, goals. exposition is a lil harder but generally, leave as much as you can to be revealed, and hint dont tell. itll make things a lot quicker and give you shit to do when youre stuck, story wise.