Most of the times, my LDs are as real as real life... too much so, in fact: I can't yet go through walls and objects because, well, I only bump in it and its physically hurts (just a bit, don't worry). Visually, it's very real, very detailed with rich textures.
However, like normal dreams, the quality may vary : mines are more imprecise in the beginning of the night, and very real on the morning.
But sometimes... dreams are more real than real life. It was the case of the my first ever lucid dream; I don't know how to describe it, obviously but you can see every detail in perfect clarity, "feel" their presence...

This was for the sensations you can get; laws of physics and "continuity" however are less real (maybe this change for more experienced LDer, I'm a beginner): You don't really need to make the full movements to open a door for example, just "think about doing it" (rather than directly going through...) and the moment after you are on the other side...