I won't carry anything in other than 9mm, .38 Special, .357 Magnum, .45 ACP. More than 45 years of packing revolvers and pistols in these calibers, no reason to change.
I don't believe a manual safety is necessary on a carry pistol -- it's certainly not on a revolver, and I am entirely comfortable with a classic SIG P-series pistols or even a Glock, SIG P-320 series or S&W M&P without a manual safety, having extensive experience on all of these.
What personal or practical reasons do you have to NOT carry any particular handgun for self defense?
I think the .44 Magnum is not a great self-defense round -- in terms of being able to shoot accurately with quick follow-up shots -- and wouldn't consider carrying anything in this caliber. I'm not gonna carry anything I'm not willing to put in a lot of practice with, with the most effective rounds in the caliber, and I'm under no illusions that my arthritic wrist will hold up under repeated practice with full-house .44 Mags.
I won't carry anything under 9mm caliber. Have seen too many folks survive multiple hits with sub-optimum rounds, including one attempted suicide (.32 ACP in the head). I won't carry anything (concealed) with a barrel over 5" for practical reasons. Won't carry a revolver over the size of 4" K-frame (excepting my Colt Python which is kinda growing on me). But, frankly, won't normally carry a revolver unless I'm in my neighborhood or have a pistol (12+1) as back-up.
Slide-mounted safety levers, not gonna carry 'em. Nothing particularly against them, just better options.
Weight is not a particular issue for me, a good belt is all I need.
For years, I was wedded to the 1911 almost exclusively. Then, of course, the M9. Heavy DA trigger, so-so in SA. After the military, I discovered CZs (triggers not much better than Berettas), SIG P-series and finally got back into revolvers. For many years, I carried the 1911, then, as Pat Rogers noted, came a time to "put down the man gun" and went to a 9mm SIG. Post-mil, was issued the Glock 23, HK USP, S&W M&P for LE jobs. But, still mainly a 1911 or SIG guy.
My practical reasons are mostly all about the ergonomics. I've found that the 1911, the Beretta, the CZ-75 and SIG P-series pistols fit my hands precisely. I just like a precise grip angle and where my first trigger finger joint hits the trigger.
And I shoot pistols much more proficiently than revolvers, alas, even after more than 40 years of working on this.
While I use striker-fired pistols, I much prefer cocked-and-locked with a nice SA trigger. If I were still working, though, would stick with DA/SA, for "threat management" -- a smooth DA trigger first pull and a crisp SA second pull, like a SIG Legion series.
Of course, all this went out the window when I discovered the SIG P-365 XL with the flat trigger. Best of both worlds.