Personally, I love the Kimber Solo. HOWEVER, there are some major early production flaws with them and Kimber has halted production while they work them out. Mostly failure to extract, though the magazine latch has also been failing on a few. I have put about 200 rounds through one and I am BY FAR more accurate with the SOLO than the Kahr PM9. Both great guns, the Solo just has the BEST trigger in its class. But, any gun that is at all unreliable is a NO GO for carry so the Solo is out until Kimber fixes things. I have 3 Kimbers and the only issue is my Ultra is picky about magazines (but is flawless with the right brand) - though the brand has its detractors, I have been happy with mine.
A friend of mine has a PF9 and I'm dying to try and shoot it. I've always marveled at Kel-tec's innovative designs. They are not the most "polished" end product, but the price tag correctly reflects that and is a great deal for the dollar.
I have always liked the PM9 but when I finally got to shoot one, I was dismayed at how crappy I shot it. I know it is me and not the gun, but the trigger pull was just not right for my hand. Also, I find it a bit blocky for pocket carry - my LCP just disappears in my front pocket, but the only slightly bigger PM9 seemed like a brick

by contrast, the Solo's rounded edges disappeared much better. Again, just me - I know many people who love their PM9s and pocket them all day long.
If I were looking for a double stack 9mm, I'd probably look to the Ruger SR9c. Heard only good things about them and they have a nice trigger, though I've only dry fired them.
I own a Beretta PX4 subcompact that is scary accurate, however I can't really recommend it because it took a lot of work. Sights were off, and the finish was crap... but it's never had a FTF/FTE ever in a 1000 rounds. Heavy little sucker though...
I prefer my Kimber Ultra Carry for IWB. I find my weight preference is for guns that are under 25oz empty. Much more than that and I start to notice the weight a lot more.