All the vDC14's are the same besides colour. The DC14's with a clutch and non clutched DC14's are the only difference and some have a HEPA filter (mainly the cltched models except the all floors) the non clutched HEPA model had a HEPA though so those two contrast.
They are all the same, but if you have a very late model DC14 in dark grey, red and with a yellow cyclone that has a samsung motor and most DC14's have a YDK motor instead.
Later models are more durable and less prone to having snapped parts but really, it's quite rare to see DC14's with cracked plastics! That's why they are such tanks :)