When gfix is running in big/corrupted databases, it would be good to "see" something happening to be sure that it is actually "doing" something, and not got stuck at some phase, or just entered an infinite loop (due to corruption).
As the possibility of adding progress bars, etc seems to be improbably, some basic information would help, ie:
Object name being analyzed
Incremental number of pages accessed for that object
Starting Time for that object (end time when job finishes)
Maybe some alert if a specific page was read more than 100 times (possible infinite loop detected)
Anyway, anything more than a black "silent" screen would be welcome. Maybe the same info can be shown when sweep is being done.