I have a question, did you get any groves on the wood with the sanding? Or do you have experience sanding? I only ask because my husband and I are arguing about the doability of this haha i saw yeah! He says "nope no way ee would ruin our floors!" This is an argument on our future hypothetical house hahahahaha
I have no experience whatsoever.
With a random orbital sander like this
http://www.bobvila.com/articles/diy-floor-sander/#.U-DVYLHvabA it is a piece of cake. The sander floats over the floor, with a 1/2" fiber mat in between the metal plate and the sandpaper. It's harder than vacuuming, because the machine is heavier, but the concept is the same. You don't have to go with the wood grain, which is really handy for some of the spaces (like near my front door) where the space is small and the wood grain runs perpendicular. No worries about sanding grooves into the floor or otherwise damaging it.
FWIW, I'm a 45 year old woman. I'm strong and healthy, but I don't have the upper body strength of most men. I didn't need it.
You can do this.
Edited to add: In 2008, pre-MMM days, I paid $1,000 to have my floors screened and recoated. The result I produced this past weekend is much nicer than what I paid for in 2008, in part because I took the floor down to bare wood before the new finish was spread. Had I paid someone to do this job, it would have cost around $2,000.
It was physically very taxing, I won't kid you on that. After work on Friday, I sanded the dining room floor perimeter and quit for the night around 11:45. I got up on Saturday at 5:45 AM and worked all day. At 8:30 PM, when I finally stopped for the evening, I was sitting in my car at Home Depot willing myself to move so I could pick up an extra lambswool pad. I sat there, telling myself "You have to get out of the car now. You can do this. A hot shower is waiting for you." Sunday was better, but still a lot of work. I'd compare it to painting the entire interior of your house, including ceilings. I'm really glad I did it, but
damn, it was hard.
I'm grateful to be healthy and strong -- capable of DIY such a job -- and grateful to MMM and this forum for giving me the confidence to tackle it.