Yeah as for size I would definitely say they are not big and get most of their growth later. I culled my June hatch cockerels in Nov for other reasons but I should have waited because the fully processed birds were just over 2 lbs. (what was there tasted great)caychris provided a lot of good information!
My cockerels are about 5.5 to 6.5 pounds right now. One hatched at the end of April just weighed 6.5 last weekend. In fact somewhere I posted his photo when he was all legs - and predicted that he would get some weight on him and some heft... and he definitely did by 8-9 months old.
The females weigh less - but my current adult females are around 5 to 5.5 pounds.
They are not pet birds and mine have an aversion to being picked up and being held...even the brooder babies---but if you allow them to sit on your hand -- they will sit on your hand walk up your arm get on your shoulder -- and by that time I put them back in the brooder... They aren't pet type birds IMO-- but they are calmer than Leghorns IMO. I used to say that the cockerels are as sweet as pie and they are safe around children...and I don't say that any longer. They are typical roosters and they are tremendously protective of their hens. They are better with their hens than any other rooster I have seen -- They really are good in that respect..it is amazing. Once I thought one was going to starve himself to death he was so busy finding food and treats for the hens he never ate any himself.... LOL He is still surviving so he must have evened it all out.
They are generally good producers. I have heard that the show-lines don't produce as well as the ordinary ones-- and that may be to be expected. I get a lot of eggs -- but not jumbo or extra large eggs... It suits me since I would rather have a large or a medium daily than an extra large every-other or every second or third day. It partly depends upon what you want for your flock. They are great foragers if allowed to free range. They have a good feed-conversion ratio. Mine have been doing well for a couple of years now - and I appreciate the longevity. Laying usually starts when the pullet is around 24-weeks old. Depending upon when that occurs - they will most likely lay through the first winter with not much attention paid to the weather... I'm in TX and we seldom get snow and the cold spells usually don't last long -- it is a matter of overnight temperature dips then milder days. After they reach 18-months they will generally molt and lay off the egg production until they have fully refeathered.
Correct Cream Legbars should all have crests - each and every one. A nice CL could be lacking a crest -- but please don't put non-crested ones in Poultry shows. For the showing circuit - it is a disqualifier to lack a crest on a breed that has a crest in the Standard of Perfection.
I don't doubt that a Cream Legbar male would get along fine with polish hens -- but I don't think that they would tolerate Polish roosters around JMO -- I don't ever let roosters in the same pen together once they have started breeding. Just the way I do it.
The cream Legbar Club Board of Directors is just now discussing some things about CLs - and the Club VP does bring up the topic that CLs are new to the USA and are still considered a 'work in progress' -- so one person's experience with their line - may not necessarially reflect what everyone is experiencing. HTH