Here is direct confirmation that we should not do floors. Althought we thought we got a lot sanded, apparently we did not. Here are just two shots. They are in the order of Before - After we sanded for 8 hours - after a pro sanded for about 2 hours (OK, maybe 3).
So - you can totally tell that the job we did was basically crap. I am so glad we did not listen to my dad when he said that our job looked OK and that it would look fine if we just put poly over our sand job.
You will have to wait a few days until I post after pictures - we can't walk on the floors for a few days.