Interesting @oldhenlikesdogs
description of the Speckled Sussex and Ancona.
My SFH behave more like your description of the Ancona in personality...but I'd never say that I've had a GREAT layer. One of the new pullets seems to be laying exceptionally well so I'll have to watch her. All my sfh are from breeder. The ones that I've see them call SFH at the various hatcheries don't resemble SFH very much...especially the roosters. Not sure exactly what they really are so I can't comment on them.
@CuzChickens
What part of the country are you located in? That hen is very pretty! Looks very much like SFH.
I tend to prefer "birds of color"...particularly black base and chocolate base with flowering. Do the Sussex have specific breed standards as far as color?
That's one think I like about SFH...being "landrace" the colors are endless. The only "loose standard" are items like leg color, no sprigs, a basic body shape. Other than that, the colors are amazingly endless. They're like that proverbial "box of chocolates"...you never know what you're going to get