Wow Mike, moving away from revolvers for CCW?!?! What is happening to this world?
Seriously, why not? It is a personal choice and if you are confident in your auto and are in seedier parts of the area so you feel more comfortable with a larger caliber (but still easily carriable gun unlike a larger caliber revolver) or more capacity, or both, why not?
That said, all metal 3rd gen S&W now, like someone else said, could be said that you are still on the same track. It is still a pretty traditional gun. From revolvers only to now revolvers and traditional metal framed autos. Of course, it is a slippery slope. I started with revolvers only for HD and theoretical future CCW. Then I got into a few autos and decided that I was just that, a revolver and traditional metal framed auto guy. Now, while I do own several, and some of my carry guns are metal framed guns (I have a CZ P01 that I might eventually use for its intended purpose at purchase, I just got a CZ 75B Compact, and I have a couple 1911 style guns in different sizes), I have a .45ACP SIG P250 in my nightstand gun safe for primary HD use, a SIG P290RS for occasional pocket duty, and a S&W M&P 40c for CCW when I'm in a carry state but don't choose to carry the Officers or Commander size 1911. About 90% of my carry is one of those autos (almost 50/50 between the 1911s and the M&P) and bit less than 10% is revolver these days. So, maybe in a year or two you'll be reporting carrying your 1st Glock or S&W M&P?
As for the weight loss, congrats. I've been following it on Facebook and you've been an inspiration (though I haven't successfully followed suit yet).