Received my renewal letter with PIN on Friday, 8/26 from Macomb County Clerks Office, almost exactly 6 months before my birthday next February, when my current CPL expires.
Submitted my renewal application online 8/26, and just received my new CPL in the mail today, 9/6. So a total of 11 days, and that includes the Labor Day holiday.
Pretty darn prompt, in my opinion!