We've had our pup for just over four months now. He's fattened up a lot since those early days. He's filled out so much that his collar, which used to hang on him is now almost too tight even though we've let it out all the way. I think he's about 65 pounds now (up from 52 when we got him). He's also learned "sit" and "stay" and "down".
He loves to jump in the creek near our house and is getting really good at returning when we call him.