I saw this video explanation of SPD recently, and I thought it was really helpful and accurate to the information I know about this disorder.
Daniel mostly deals with sensory over responsiveness, as well as discrimination issues (being able to know where certain sensations are coming from and also interpreting what they mean).
Jaymz also has some sensory issues which interfere with his everyday functioning, and he is definitely more under responsive to sensory input than the average person (and certainly so when compared with Daniel). Ironically, when I showed Jaymz this video he was so distracted by the audio that he was unable to read the words, so we had to watch it on "mute" for him to glean the content from it.
I continue to be fascinated by how our brains work, how they are all different from each other, and what we can learn from those incredible differences.