My last renewal was in 09 and it was 88 days from the the day I filed at the westalnd office until it was in my mailbox. My wife renewed again this summer and hers was about 75 days. My original in 01 took 8 months, I don't think that many people are waiting that long these days though, many of the bugs have been fixed. I would be surprised if it takes longer then 90 for you.
Westland has free parking, detroit cost 6 or 8 bucks and westland doesn't have the security guards like detroit has.
I would call (westland) the day you are going and ask about pictures. I have read that wayne county now forces you to buy your photo from their digital camera now, but some days their camera is broke.
The good part is that wayne county has the "new style" CPL once you get it. It looks just like your drivers license now rather then like a 2 year old made it like the old style does.