I got a Beretta 92X Centurion (similar to the G45 dimensions) for $429--it was $529 and there's a $100 rebate (not sure if it's still going on). If I had it to do over again, I'd likely go with the full-size...since I NEVER carry it or the G19 now that I we have so many other options (43X / P365).
The 92X gives me everything I want in an M9--replaceable sights, vertec grip (with the full grip option), light rail, decocker only, etc. I love the MEC-GAR 18rd FLUSH mags, but also have a few mec-gar 20rd mags, and a few beretta mags (18rds but sort of extended-fit). The 92X is my go to HD pistol when there's no time for the carbine.
However, due to weight, I think of my G19.5 MOS as my go-to-war gun, and I have like 20 mags for it. In that kind of scenario, I'd be depending on my carbine WAY more than my pistol, so it's just extra weight 99.99% of the time. Due to weight, simplicity, durability, and reliability, most of the Tier-1 units (in the US and all over) went to Glock...and then moved from 40 back to 9mm.