I've seen a few but haven't really focussed on them as I prefer a smaller dog.
Bull/greys would have similar coat type, similar colour, assuming height and general proportions are additive, then yes I probably would expect them to breed fairly true to type. However as regards F1 versus F2 if there was a genetically deaf white bull parent then this might not be noticed as a problem in the offspring until breeding two lurchers with very slight hereditary deafness... and thus potentially getting a few pups with very poor hearing in the F2 (there are a few deaf lurchers around in rescues with a bull/grey look). Similarly F2 bedlington/whippets are very nice - nothing wrong with the shape/size/drive BUT you can't guarantee your pup won't die of copper toxicosis so a F1 or a back cross to a whippet is much safer.
With labradoodles as I understand it the concerns are mainly about things that are (like the copper toxicosis) controlled by relatively simple dominant/recessive relationships. The labradoodle at the that start of this thread appears to be a take after a grandparent. Coat type is I think fairly simple (Sara maybe mentions it is a dom/rec somewhere in this thread )
I wonder if you breed bull/greyhounds whether the litter number changes according to the generation? Just curious...
I'm not referring to dogs with a bull/grey look but bullxs bred specifically for there job. The bullxs bred properly are all strong dogs with the same characteristics.
As far as litter size I can give you an example, a dog called rio was put to a halfx bitch and she had 11 pups, he was then put to a f2 bitch and produced 12 pups. He was then put to a cold bitch producing 6 pups, before being put to his f3 daughter producing 10 pups.
I say dogs with a bull/grey look because I treat most lurcher pedigrees with some skepticism . I'm sure you know a lot more than I do about the bull/greys. I know a little more about the genetics of the smaller lurchers from a buyers rather than a breeders perspective.
I just got a 8 week old labradoodle. He is multi generational meaning his grand parents (even great grandparents) were labradoodles. To be honest he does not resemble a poodle or a labrador. So yes I would say its hard to discern what they will look like if they are not from a multi-generational breeder and you are basically getting a dice roll.