Testing 5.5.5.2 I see some reduction in timing but the most noticeable savings is in memory utilization:

Peak appliance used memory during rake db:migrate
5.5.4.1 - 11.3GiB
5.5.5.2 - 2.7GiB

db:migrate Timing:
5.5.4.1 - 6hr 45m
5.5.5.2 - 5hr 43m

Database still bloats on event_streams:

event_streams - 17GB


vmdb_production=# SELECT pg_size_pretty(pg_database_size('vmdb_production'));
 pg_size_pretty
----------------
 37 GB
(1 row)

vmdb_production=# VACUUM FULL event_streams;
VACUUM
vmdb_production=# SELECT pg_size_pretty(pg_database_size('vmdb_production'));
 pg_size_pretty
----------------
 26 GB
(1 row)


FixSerializedReportsForRailsFour decreases in timing:
5.5.4.1 - 21999.6597s
5.5.5.2 - 19057.7571s

As 

RenameEmsEventTableToEventStream increases in timing:
5.5.4.1 - 876.8407s
5.5.5.2 - 1194.6601s

Though net affect on db:migrate is lower by an hour in this testbed.

Created attachment 1181613 [details]
Files from migration on 5552

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2016-1488.html