I always set a style specifically for each comic that matches the overall feeling. But with misc drawings the style I often use is slightly exaggerated and stylised, but with relatively realistic proportions. I like it because the exaggeration of it helps make facial expressions look better.
Being able to vary style from stylised to realistic opens many doors if you're, for example, looking for a job, so that skill can be an asset. One style could work just as well, especially when you're experienced with it. Personally I wouldn't want to be an artist of just one style. It's like always wearing clothing of just one colour. It gets boring and you'll never experience anything new. Not everyone wants to be that adventurous, of course. If you've found something you really like, stick to it and make it your own.
I'll share here one of my works where I played with both realism and stylising in the same piece.