I know the obvious difference of diaphragm size. but what are the other differences? does one sound better than the other?
not better, different. Small diaphram mics are usually brighter and more detailed while LD mics tend to be very natural, not quite as detailed and produce a much deeper and smoother bass IMO. After running schoeps for a long time, and now also running the ADK TL's they are both very different and will come in handy in different situations
Check out the Dpa microphone university.
http://www.dpamicrophones.com/
A section can be found in the technology guide.