Informix databases usually don't need to be reorganized. Unlike Oracle, informix does reuse free space, caused by deletions.
The only reason why you should reorg your tables in Informix is that you chose a wrong extent size for your table.
Chek the number of extents allocated to a table in the sysptnhdr table in the sysmaster database.
The partnumber can be joined with the sysptprof table to get the exact table name.
the nextns column displays the number of extents.
For a 2K page size 200 extents is really alarming.
best to keep under 20 extents.
I'm also come from Baan/Informix side.
I think that the best way for you to reorganize the tables/indexes is to export & import the company data using bdbpre & bdbpost utilities. If you have large extents you may need to adjust your inf_storage file to change your tables extents initial and next size.