pg_dump slower than pg_restore

I'm running PG 9.3.4 on CentOS 6.4 and noted that backing up my database 
takes much longer than restoring it.

That seems counter-intuitive to me because it seems like reading from a 
database should generally be faster than writing to it.

I have a database that pg_database_size reports as 18GB, and resulting 
dump is about 13GB in 27 files (split creates them as 512MB).

A pg_dump backup -- with most of the data stored as large objects -- 
takes about 5 hours.

But restoring that dump takes about 2 hours.  So it's taking 2.5 times 
longer to back it up than to restore it.

My backup script runs vacuumlo, then vacuum, then analyze, then pg_dump 
--format=c --oids $DB

I actually push pg_dump output through gzip, gpg and split on 512MB 
files, but they shouldn't matter too much I figure as I have to run cat, 
gpg and gunzip before pg_restore.  In fact, my restore should have been 
at a disadvantage because I used '-v' and showed the results to my ssh 
term over the Internet which includes a line for each LOID, and the 
postgresql.conf had 'ddl' logging on (which I suspect I can turn off in 
future restores to speed things up a bit).

Is there something that might be wrong about my configuration that the 
backup is slower than the restore?

Thanks,
David