My experiences are a sample of one- but it is what is true for me, so that is all I care about.
The Ruger P97DC was my first .45acp handgun.
It is not something I want to pull out for bragging rights. I isn't something I'd pull out for pictures. I isn't something I'd try to impress my friends with.
But I sold a H&K UPS 45Compact, a Sig P220Combat and a S.A. Loaded blackened Stainless target model 1911 because I was consistently more accurate with the Ruger P97.
Since then I've added some other 'toys'. And some I am more accurate with [all of which are 1911s of some form- imagine that].
However, I have NO doubts that the Ruger will go bang every time and save my life. It may not get me 2" 8-round groups at 10 yards [but that is because I need more practice]. It may have an 'odd' recoil impulse [due to unique recoil cam action in rod]. It may have only 8 rounds [but I live in California, so only give up 2 to other models]. It may not have a light rail underneath [neither do 5 of my 1911s].
Yet, I am NEVER in doubt of its reliability.
I find the reset a bit longer than others have mentioned, but love the fact that my DA pull is around 8lbs and my SA pull is around 3lbs, with stock springs. My Walther P38 has a DA pull of something like 16lbs, so this feels like heaven!
The let-off is a 'rolling break' on mine, so I am not stacking it just before it pops. I find this makes me focus on sight alignment more- and I don't flinch as often.
I like it enough that I bought a complete parts kit for it for $100 about 4 years ago [
everything, except the frame itself].
I find myself preferring 1911s now a days. I find the Glock design interesting, as I have a 30sf with a .45-10mm conversion barrel, a 10-to .40S&W conversion barrel, and a .22lr top end. It is fun to have 4 calibers in one frame. I find the 'feel' of the M&P .45 full size to be the bee's knees, when compared to anything other than a 1911- and the APEX DCEAK in it is NICE.
I don't get the P97 out much any more.
However, it is one that I have more confidence in than about anything else I've shot. It just isn't as 'inspiring' in the hand.
I found the P90 too bulky for my hand, and the P97 was a better fit. I just added grip tape to mine to keep it from sliding.
I never could justify the P345, as I disliked the LCI, I disliked the 'feel' of the grip in my hand, and the only thing I liked more about it was the light rail underneath.
The SR45 was a striker fired, and felt even odder in my hand [and I am in California- it didn't make the gun list before the list froze].
One other thing to consider, depending on where you live. Rock Island Armory 1911 Tacticals are a good value for an entry level 1911.
I have 3. I have a Caspian frame/slide with all EGW parts in it also, and it IS better than the RIA Tactical- but it also cost almost 4 times as much.
I mention this as 1911 parts are ubiquitous, and Ruger P-series .45acp handgun parts are drying up FAST. If your Ruger P97 breaks a firing pin or needs a sear spring- good luck.
If a RIA 1911 Tactical needs one, you are good to go.
I don't know the KAHR .45s from experience. I had a Kahr K9 and liked it, but found the magazine design annoying, as the first round in my spare mags would work loose in the mag holder. I don't know if the .45s have that problem.
Whatever you decide, good luck!