Compare libraries across systems or on the same system

All,

Trying to compare libraries, ie. the complete set of objects in a
particular library vs. the set of objects in another library, either
on the same machine or on a different machine.

Right now, I'm doing so via querying the output of DSPOBJD like so...
with <<snipped code adding prefix to columns>>
, FO
as (select * from SYSA left outer join SYSB
using (ODOBNM, ODOBTP, ODOBAT)
UNION ALL
select * from SYSA right exception join SYSB
using (ODOBNM, ODOBTP, ODOBAT)
)
select * from FO
where o_odlbnm is null or p_odlbnm is null
or o_odobsz <> p_odobsz or o_odcpvr <> p_odcpvr
or o_ODSRCD <> p_ODSRCD;

All boxes are at v5r4, and should be at the same PTF level...

First of all, is there a better way to do this?

Second, I notice that some of the differences in sizes don't seem to
have any reason...

Example for one PF, which has 0 members and the same format on box boxes:
System A, object size 20480
System B, object size 28672

I think I recall reading something about why this is the case, perhaps
because system B has 6TB of disk and System A has only 0.85TB?

Is there anyway to account for this in my comparisons?

Thanks!

Charles