I've seen this kind of attitude many times and in most cases until people
were prepared to deal with the facts and data they were unable to solve
What you need to do is measure all the parts of the process on both machines
and any equipment in between and identify which part is the hold up using
benchmarks and data. Locate the problem with numbers not prejudice.
It may well be the iSeries that is the problem, but with your approach if it
isn't you'll *never* get it fixed.