There isn't a preference, to me they work differently.
The Coles Jaws I can tighten onto a form ( or expand into the the shape permits it) and therefore I feel it has better holding power, they are also smaller, so used on smaller items.
The Longworth, I made to the maximum diameter of my lathe's throw. It has fewer button's, therefore I run it much slower and only for fruit platters that are quite flat in section. As it grips by the action of the rotation I don't tend to trust it quite as much. Certainly not without the tailstock brought up anyway.
If you Google you will find manufactured ones now available and even small homemade ones that would equate to the Coles.
With either tail support is highly recommended because (hard to explain) when moving the gouge across the timber, you cause a 'lifting' action which if you are not careful will dismount the wood.
The homemade chuck to over-come this is the donut chuck (Google with American spelling)