Regarding year round eggs -- This is why having two breeds (even if you only have a rooster in one breed) can be of benefit. Some one emailed me the other day about Light Sussex chicks this spring. I have a standard "warning" about light susssex ( not really a warning but a heads-up) they lay through out the winter and stop between May - June and won't pick up again until September-October so I will always suggest they get a second breed (Not from me because I only have the one!) often times I suggest a production red - or something of that nature to balance out all year production.
I prefer one breed for eggs. By having both a generation of pullets and hens, I am never am without eggs. Even when the hens are molting. There is some seasonal variation in my flock, but I am never without eggs.
I could not call a breed or strain productive that took an entire season off unless the were mothers and rearing chicks. To me, those girls are still working.