I�ve been carrying a 30SF daily for over a year now and I really like it. It hides well under a polo shirt with the optional 9 round magazines, and it also works well with G21 magazines. It has been 100% reliable with 230 grain Blazers and Gold Dots. I also have tested some Buffalo Bore 255 grain HCFN +P for the woods that chronographed at 923 MV out of the stock barrel. When I got the gun, I also bought a KKM barrel for lead handloads. It does not like 200 grain SWCs. I maybe have not figured out the trick with those. Hotter ones definitely function better, but it is not 100% with them.
I also have a G36 and, by switching out the 30 top end, tried the hybrid thing that is now a 30S. I don�t get the love. The weight difference is 3-1/2 ounces. A 32-1/2 ounce .45 (30SF with 9-230 grain bullets) is pretty light to start, and I see no reason to go lighter. The grip is the same width anyway, so it does not help hide the gun any better. Some people apparently think the difference in slide width makes a difference in IWB carrying, but it does not to me. I have mistakenly worn the 30 IWB when I thought I was carrying the 36, without realizing it. The 36 is just a backup at this point.
From what I read, the Gen4 30 is a just 30SF with some extra backstrap adapters to make the grip longer (which I certainly do not need), plus the Gen4 stippling and mag release changes.
I noticed your post with the KKM barrel and the G30. I have the same set up and am shooting a truckload of H&G #68 205g cast bullets out of it. I struggled getting them to fit in the KKM barrel but ended up reducing the OAL and then ran the loaded round through a Lee Factory Crimp Die with the top of the die removed using a "pusher" from Lee's cast reloading supplies. It resizes the whole round and since then the G30 with the KKM is running without a burp.
There are a lot of U Tube videos on the Lee die, as you many know.
