2 years and 5 months old boy. He speaks a lot, but doesn't say much. No autism. How worried should we be? ?

My son is 2 years and 5 months old. He speaks a lot, but doesn't say much. He says the same words over and over again. However, his vocabulary is about 35-45 words and about half are not right. For example, he says Pea instead of Peach. I thought maybe he could not pronounce the "ch" sound, but he could say cheeze (cheese). I was a late talker. So was my dad. My mother-in-law beleives that my wife was also a late talker. So were some of her uncles. My wife is very worried (she is a teacher and a worrier). I am less worried. I think that he will grow out of it. However, I don't have any stats on this. How many children have this issue and grow out of it? How many don't grow out of it? (I don't know any adults with speech problems). How many kids have perminent problems in life/learning disabilities because of this, even with treatment? More info: My sons hearing is fine. He understands everything we tell him. He knows all his alphabet and can name almost all of them. However, he cannot prenounce some of them correctly (Ha instead of aich (H)). A speech therapist has ruled out autism. How worried should we be? PS I mistakenly placed this in Newborn & Baby first instead of Toddler & Preschooler.