Lot's of info and opinion here so I'll throw in.

66- I like the S & W 60, even tho I traded one.
Keeping the Hammerless Airweight version because of weight. Yeah,  you're  not going to practice a lot in one day as it's hard on the hand and it's definitely not your 25 yrd firearm, but it's SUPER light and with specific short bbl +P SD rounds ( I load Hornady CD+P), it's an efficient CQB firearm. At just slightly over a lb loaded, it's easy to carry all day long.
   
       On several occasions, I too carried my GL19 and 2 mags  in excess of 8 and 9 hrs. Yup, pain in the back and legs but then again, I was standing all day.
On the second day of both of these occasions, I swapped out to carrying my GL43 w/Pearce +1 extension (22 ozs) and 2 mags  and never knew it was there all day long.
Granted, again it's not your 25 yrd firearm but you're talking close range defense and aren't most shootout encounters within 5-8ft ?

All day long I'd op for the 43, under 6 hrs I'll take the 19.
Worried about the 43's  7-8 round max? Improve your reloading technique ! 
Either case I'd like the .38 on my ankle which suffers no ill weight issues.

The 19 is a good choice because it holds more rounds compared to the 43 (7) and the Shield (9).  And the size isn't that much more.

At least if its uncomfortable, you know that the gun is still there.  Maybe wear a garment under the holster (underarmor dry fit, or wife beater tank, etc...) on long carrying days.

I'm not a fan of the fanny pack because access is restricted if needed to draw quickly.  And the zipper makes a noise.  Also if robbed, the robber would ask to open the pack or for it.  Then if he sees the gun, possible he might shoot you.  Where as IWB, it's hard to see.

The fanny pack suggested pulls open very quickly and has very little restrictions.   I'd say it's on par with any IWB option.

From my research on self defense shootings, most were 3-5 yds, and that is why I practice drawing from concealment and firing from the hip at these ranges. 7 yds and out, I raise it to eye level. I think I will start practicing firing while moving from one location to another.

I prefer appendix carry. Anything more than a 3 o'clock position feels awkward and slow for me.

From my research on self defense shootings, most were 3-5 yds, and that is why I practice drawing from concealment and firing from the hip at these ranges. 7 yds. and out, I raise it to eye level. I think I will start practicing firing while moving from one location to another.

I prefer appendix carry. Anything more than a 3 o'clock position feels awkward and slow for me.

Hey RN
2-3 yards or 3-5 yards, its still CQB.
I too I practice drawing from concealment and firing from the hip at these short distances and at  7 yds or more (based upon the "attacker can cover 21 ft in 3 seconds or less" ) I raise it to eye level.
As I have gotten pretty good at "instinctively shooting" my compound bow, I will be experimenting with  "instinctively shooting" my handguns. 
I mean, that's what you're already doing when your shooting from the hip, right ?

The new standard changed from 21 ft to about 30 ft.

I would feel more comfortable being 300 ft away with my AR15 and the bad guy has something like a .25 Auto LOL.