OK, have pretty successfully confused myself so far over this. The S&W site is singularly unhelpful on the subject, thought I'd confirm with the vast repository of FTF knowledge here.
I got the following info this morning via email from the guy who imports MPs in Aust -
Yes, the M&P PRO series has a fixed rear sight as does the standard M&P9L.
> I wouldn't worry about an adjustable rear sight. I have pistols with both
> adjustable and fixed rear sights. An adjustable rear sight can provide
> benefits AND drawbacks.
> Benefit/drawback of fixed rear sight:
> 1. Once it is sighted in it will never need adjusting
> 2. You will need to tailor your loads to ensure that point of aim
> becomes point of impact
> Benefit/drawback of Adjustable rear sight:
> 1. Can be adjusted easily for point of aim to point of impact
> 2. Can be easily damaged and affect sighting
> In my opinion the fixed sight is the better of the two. Once the load has
> been tailored to the pistol you will never need to worry about adjusting the
> sight out to distance.
> In my M&P's (I have 2 of them, exactly the same setup on both) I have them
> fitted with a fibre opric front sight and fixed rear sights. My loads shoot
> about 1/2 inch below point of aim at 25 meters. Group size is around 2
> inches @ 25m. Good enough for IPSC and for me.
> The load that I use in my M&P is 3.6 grains of AS30 powder, a 135 grain
> round nose projectile and loaded to 1.14 inches Overall Length and a taper
> crimp on the case. This will get you right in the ballpark for POA/POI but
> may need some adjustment for individual pistols.
First off, most of the details re handloading go way over my head, fascinating though they are
however for some weird reason I had been under the impression that the 9L had adjustable sights...but apparently not. My club's captain had been fairly particular in saying last week that I should get a gun with adjustable rears, and reading the above email, I can now see why. Not likely to be reloading in the immediate future.
So...any point considering aftermarket adjustables in these circumstances? I have about a month to wait now before the importer gets back from a trip to Melbourne. Time to decide...time to amass all the other stuff I need...learn how to clean the damn thing, etc