I've been looking at properties in both high rental and high ownership areas in a particular city. In your experience what area is better to invest in?

I will assume areas with a higher number of rentals will be more competitive and have more C and D tenants than areas with higher number of owner occupied homes..

For example, purchasing a duplex on a block or area where they have a lot of duplexes. Is that a smart area to invest in? Or am I better off finding an area where they have fewer duplexes/multi families?