Frequently updated tables

I've been down several roads about how to handle data that has to change
on a very frequent and rapid manner.

Think about summary tables, WEB session tables, etc. As great as MVCC is
for the vast majority of uses. The overhead of updates and deletes can
kill a project that needs to constantly update tables.

In most cases, the answer is just not to use PostgreSQL for that, but then
you are stuck with Mysql or something worse.

Would having a special class of table that is marked for frequent updates,
which causes the system to lock and update in place, make sense? Is that
even possible?

There has to be a way of making PostgreSQL able to handle this class of
problem. Anyone have a reasonable idea?