I resurfaced all my wood floors using a rented drum sander and smaller orbital. It's doable, but I think if I were to do it again I would hire it out. My floors have a lot of small 'chatter marks', and the surfaces aren't as smooth as a professional job. The process was very drawn out as well:
1. Sand with low grit sandpaper
2. use smaller orbital sander to get corners and tight spaces
3. let dust settle
4. vacuum room
5. repeat 1-4 with finer and finer sandpaper grains
6. once done, use tac cloth to get every spec of dust you can
7. Apply polyurethane to floor with lamb wool applicator
8. let dry
9. wood grains have now raised a bit, resand with very fine sandpaper
10. vacuum and tac cloth for dust
11. more polyurethane
it hurt just typing those steps out. I'm very DIY oriented but I didn't feel the results were good enough for how much work it was and how relatively inexpensive it is to hire out. YMMV, and maybe I just didn't do a good job.