My L2 french teacher noted that she can always tell who in her classes reads and who doesn't — the latter have better pronunciation but only over a far narrower range of utterances.
Yes! I had much worse pronunciation (and slower speech) in my two years of studying English than people with comparable time into the language, but then the cumulative advantage of knowing it better allowed me to engage in longer and more interesting discussions which, in turn, helped me hone both accent and speed.
