Getting wood floors refinished - oil or water based varnish?

replying to strangways, Iggy wrote: They're really about equal in durability. Oil has slightly more solids, costs less, takes 3-times longer to cure and lends an orange or amber tint to the stained or unstained floor. Water is very clear and doesn't change the stain or natural color, the 4-coats can possibly be done in 1-day for the room's use tomorrow. Either 1 may need re-coating every few years, depending on how finicky you are...normal people just let them go until they die or move.

Oil finishes tend to have a slightly yellow cast. Water finishes are more clear. You may or may not like the difference of one over the other, if you do, let that make your decision.

Oil will also have a bit longer lingering of odor when finished. Both are pretty durable but I have little personal experience to give a definitive answer.

Yes. The oil is much more durable.

I don't have experience with floors, but outside, on stamped concrete, the solvent based clear coat products are more durable and last substantially longer. The problem is that the hippies have regulated them so that you can't legally buy the solvent based ones in many states now. The downside is they smell while drying and that could be a factor, or not, depending on what area in the house you're doing.