You would be pleasantly suprised how a full steel frame and fork and squishy tires feels after a while. 95% of the time I do not miss suspension at all.
I agree carbon seatposts are useless on a mountain bike but carbon handlebars seem to damp vibrations for me, especially on high speed descents. Maybe it is all in my head, but I don't think so. I suspect you would get the same effect from steel bars or titanium bars.
You mentioned that the rigid bike has a steel frame and the front suspension bike has a aluminum frame.
I would say go with the rigid also.
The 5% of the time I miss front suspension? Riding many consecutive days. It tends to beat you up a bit. Maybe I am a wimp or am just getting old, but I usually only ride on trails with rigid bikes 2-3 days per week, so I have some time to rest.
And like redfooj said, you can always wimp out and put on a susp. fork