AAhhh so pleased to hear your older brother calmed down a bit. My sister certainly did, I think she was just very clever and really wanted to communicate but couldn't, as soon as she could, she was lovely. My brother is still a bit of a bugger now to be honest and loves to cause trouble and bitch about people, yet was so placid as a baby.
My ds does seem very independant, if I try and help him with something he seems to resent it! (Eg, earlier, he was holding his cup the wrong way so he was having to tip it soooo much further than if he had the spout turned the right way, I tried to turn it for him to make it easier and he screamed at me and threw the cup accross the room!)
It can be tiring but I'll take anything over the way he used to be so for me it seems quite easy now! I find it quite reassurring that he has such a strong mind but maybe I'll regret thinking that as he gets older! He is able to entertain himself loads though so in that respect I am very lucky. He doesn't seem to need me sat his side or helping him with things, he is quite happy as long as he can keep looking up and checking I'm somewhere in the room.
I'm sure when he's older he's going to be running off with his friends while I sip a cup of tea from the sidelines!
Really hoping you get an easy going 3rd child, I always think they must get easier as you go on as the older children can sort of help entertaining them a bit. I guess I'll find out as (crazily) me and dh are planning a 2nd in the next couple of years (eeeek!)