Exchequers are just like any other leghorn temperament wise.
I have birds from Sandhill and from Ideal and the sandhill birds are no good in my breeding program. The eggs are small(although they do lay daily), and they must have a lot of Ancona blood because they have a lot of a pattern to their markings(aka most feathers are white tipped) and speckling on their legs like you wouldn't believe. Total spazzes like other leghorns.
The Ideal birds suprised me, a lot of white(which is a very good thing) in no particular pattern, very little to no speckling on the legs and temperament wise a lot better then the Sandhill birds. One of my Ideal cockerals acctually likes to be picked up and pet and the girls will not die of a heart attack when you hold them(had a white leghorn do that to me, screaming one second and slumped together dead the next, scary).
Dunno about eggs with the Ideal Excheqs yet, they should start laying any day.
Anna