whereas in Erlang (IIRC) ETS cause some issues with GC

There isn't any at all for ETS:

   Note that there is no automatic garbage collection for
   tables. Even if there are no references to a table from
   any process, it will not automatically be destroyed
   unless the owner process terminates. It can be destroyed
   explicitly by using delete/1. The default owner is the
   process that created the table. Table ownership can be
   transferred at process termination by using the heir
   option or explicitly by calling give_away/3.

Of course, you'll seldom be using ETS directly, but rather through Mnesia.

From: http://www.erlang.org/doc/man/ets.html