I think that in LD, consciousness resides in the physical body and is of low-quality, with impaired mental function, limited recall of daily activities, a lot of fantasy constructs and basically an internal experience. The environment, if located in a known physical loaction does not accurately reflect the actual physical conditions, weather etc at the time.
In OOB on the other hand, consciousness resides external to the physical body, is heightened, with expanded senses, greater sense of reality, 360 deg vision sometimes, communication by telepathy rather than spoken etc etc. The OOB environment, if located in the physical world can be an accurate reflection of the physical at the time.
There may be a sliding scale between the two, based on the mind-split between physical and OOB consciousness, ie if most of your consciousness is in the physical you will have more fantasy, lower awareness, etc. If most consciousness is OOB then expanded consciousness, heightened awareness, clearer senses etc.
I think they did some EEG research on several OOBers and found that EEG patterns when OOB were quite different from REM sleep and LD patterns. LD/OOB... they're quite different.
That's what I think anyway...