I have shot a few of the micro-9s over the years and handled nearly all of them. One of my closest friends had a Kahr MK9 Elite for a few years and then traded it on a PM9 so I have had the opportunity to fire both extensively. I rented the Kel Tec P11 many times, and I own a PF-9. While not 9mm, I also have a Ruger LCP (.380) and I used to own an NAA Guardian (.32acp) and Bersa Thunder .380 (and shot a Kel-tec P32 and SIG P230 several times) for experience with other small pistols. I own or have owned several small-framed snub revolvers over the years (Taurus 605, Taurus 85CH, S&W 442, Rossi 461). I also own a SIG P290RS which I bought several years ago. Out of all these deep concealment/pocketable CCW guns, my SIG P290 is one of the best. For occasional pocket carry and regular tucked IWB carry it is tied with the (double the price) Kahr MK9 Elite as my favorite, and is only beat out for regular pocket carry by the Kahr PM9 due to the Kahr's lighter weight and smaller size.
I find it easier to shoot than any other small gun. Its recoil is quite mild for such a small and light gun. My Kel Tec by comparison is outright painful to shoot, comparable to a .357mag snub. Even the terrific Kahr PM9 is no where near as comfortable to shoot. What this translates to is quicker follow-up shots which can be indispensable in a self-defense shooting, and more practice for better accuracy and familiarity with the gun. Also, I find it is much more accurate than such a small gun has any right to be (comparable to guns the next size up).
The gun has been 100% reliable so I absolutely trust it in a self-defense situation.
The biggest complaint most people have is the trigger. A hammer-fired DAO gun will have a heavier trigger than a SA, DA/SA (once transitioned to SA mode) or most striker fired DAO triggers. However, while it is longer and heavier than some other options, it is a very smooth trigger. As a revolver shooter, it reminds me of a nice DA revolver trigger pull. So, I like the extra safety of the longer trigger pull (you have to mean to pull the trigger) coupled with the comfortable butter smooth trigger pull.
I would agree that the take-down can be somewhat difficult. Not that it is complicated, but with the small 9mm design, you have a very stiff recoil spring. That can make it take a little work to take down, but anyone with decent hand strength should be able to handle it without problem.
I love CCW type guns, most of my handguns would fall into that category (even though I only part-time CCW due to MD laws so I only carry when visiting a state that honors the UT non-resident permit). I have quite a few in this category. If I could keep only one CCW type pistol, the P290 would be on my short list (along with the larger but modular, thus quite versatile, SIG P250, and the near perfect all-around gun, a 3" medium frame .357mag revolver).