Huh, even MySQL and postgres are not apples to apples - we are just now launching a service in MySQL instead of our standard postgres because MySQL has features that postgres doesn't (better connection pooling, potential data partitioning)
For others reading your comment though, I did want to list some things I have used with Postgres that relate to connection pooling and data partitioning:
I would probably say MySQL and Postgres is apples to apples just different types of apples (granny vs delicious). Their differences are not as big as a regular relation DB vs. a columnar DB.