I am thinking of getting a Beretta 92FS or an M9. I see that the old M9's had problems with the slide breaking and flying off. Some of the articles I read say that the FS model was made to fix this issue. Does this mean that the current M9's do not have the upgrade? I would have thought that both models would have been upgraded, but one article I read said that the M9 does not have the upgrade.

The lack of lawyer markings on the M9 is appealing, but I don't want to worry about a slide hitting my face.

Also, how much bigger is the M9 grip than the 92FS? Is it that noticeable?

I don't mean to sound like a jerk here and that is not my intent. I started to write out a reply but I realized I would be wasting my time. Instead I recommend you watch this video. Yes, it is 41 minutes long but it is very detailed. He discusses the M9 program, the M9 pistol in detail and even discusses the slide cracking problem, (which was blown way out of proportion and is not an issue at all today). Seriously, watch the video.



As for the grips, the 92FS has a small radius cut to the backstrap. The M9 does not have this radius cut and is straight. The image below shows what I am talking about. *not my image pulled it from the Internet.

The m9 has the standard upgrade to slide capture in event of breakage which even with exposure to countless hundreds of pistols in my military career ( was on a military shooting team and between the extra use the team guns got and being at matches with hundreds of m9's on the line if it were going to be a significant issue I suspect I would have seen it but never did- vastly overblown)  
All the upgrad is so you know is an oversized hammer pin that mates with a grove in the slide - to know for sure if looking at say old used guns is with the slide locked open and viewed upside down you will see the extra groove cut into one side of the bottom of the slide rails

Excellent video. I watched the whole thing this morning.