Like:
1. interior space, particularly ability to sleep inside
2. civility on the road (at least compared to my D1)
3. engine reliability - just routine maintenance for 140K
Dislike:
1. lack of break-over clearance
2. no gear options for those running more tire (currently on 33s)
3. sheer weight (this results in broken parts, poor range/mileage, etc)
When asked about the D3, I generally tell people it's really good off-road 'up to a point'. Try to push beyond what it's comfortable doing and you'll quickly find out it's just not worth it. It's a good 'overlanding' platform but not so good for more serious technical work. Mine currently gets used for the easy/long trips like Death Valley or Mojave Rd and the D1 takes over for the shorter but more challenging trips like the Rubicon.