What are the pros and cons of various hardwood floor finishes?
I have done both a refinish and a new install, and did a bunch of research before choosing.  These are my generalized conclusions about the different choices:

Linseed / Tung Oil

Pros:

Easy to apply
Relatively durable
Quick curing and drying times

Cons:

Will darken with age
Provides very little protection against wood damage


Oil based polyurethane

Pros:

Durable
Low maintenance

Cons:

Long dry times in between coats (~8 hours)
Long time to fully cure (~30 days).
Yellows over time
Strong odor during application and cure
Requires some skill to apply correctly


Water based polyurethane

Pros:

Durable
Low maintenance
Easy to apply
Short dry time (~3 hours)
Short cure time (~7-10 days)

Cons:

Short dry time requires a &quot;wet edge&quot; when applying.
Provides less protection than Oil polyurethane



I don't have personal experience with the Tung/Linseed oil approach.  Both of the areas which I was working are relatively high traffic, and I did not want to have to worry about damage to the wood surface.
I have seen the Oil-based poly done, and it is a production.  It usually results in evacuation from the house because of the VOCs in the finish.  The long cure times made it a deal breaker for me, because the areas in question were main walkways in my house.
So, in my case, I chose to go with the water based poly.  It is durable, comes in several finishes (satin to high gloss), and is maintenance free for many years.  It is easy to apply, and dries very quickly in between coats.  It can be applied without specialized brushes or equipment.  You can sand, stain, and seal your floors over a weekend, and they will be ready for walking 24 hours later, and will be fully cured a week later.  This is a really good choice for a DIYer, and I would not hesitate to use it again in the future.