This question will get more interesting responses if it was qualified as: "Does anyone run Postgres without PgBouncer for non-trivial workloads?" Because, as we can see from the comments so far, lots of people are going to say you don't need it for your blog that gets 10 hits a month. I've personally never heard of anyone not using PGbouncer, or some connection pooling proxy, for reasonably concurrent workloads. PG's…
yes, if you control the clients and do client-side pooling.