I shot the Beretta Nano the other day. It was super accurate - I made one jagged hole at 21 feet with 124gr Lawman. I was also impressed that it ate 115gr Federal Aluminum.
I liked the fact that it has last shot hold open without a slide stop lever. The slide stop lever - (dare I call it a slide release?) on my CM9 is in the way.
The trigger on the Nano is OK.
I purchased the CM9 because I wanted a trigger similar to the R9 but I couldn't afford another R9
And also because of weird Illinois gun laws, I didn't need a firearm as small or as light as the R9 for my second firearm - there is this thing in Illinois called "transport" which allows a person who has a FOID card to have an unloaded firearm in a case for purpose of transporting it. The magazine can be with the gun but not in the magazine well. A court ruled many years ago that a fanny pack constitutes a case. A person can "transport" in Illinois almost anyplace except a school, courtroom or Post Office.
There are a lot of places in Illinois where you cannot carry a loaded firearm on your person, but you
can transport.
The Nano is a lot larger than the R9 and heavier.
Rohrbaugh R9Caliber: 9mm
Barrel: 2.9 in
Length: 5.2 in
Height: 3.7 in
Slide Width: .82 in
Width at thickest part of pistol: .95 in
Weight: 13.5 oz, magazine 1.6 oz
Capacity: 6+1 Rounds
Beretta NanoCaliber: 9mm
Barrel: 3.07 in
Length: 5.63 in
Height: 4.17 in
Width: .90 in
Weight: 17.67 oz
Capacity: 6+1
It is about the same size as the CM9 so I think I could pocket carry in jeans but not comfortably. Kahr gives the overall length of the CM9 as 5.42” If you measure just the slide from the rear to the muzzle end, the slide is 5.4375” So it is closer to 5.4” than it is to 5.2” - that's just the slide. But that isn't really the OAL of the CM9. Putting the gun in a box, and putting the top of the slide against one wall of the box and sliding the gun until the rearmost part of the pistol touches another wall of the box, and measuring from there, the Kahr is actually 5.625” long. This is similar to how guns are measured with the IDPA box test if people are familiar with that. I didn't get a chance to measure the Nano in a box but it looks to be about the same size as the CM9. I don't think I could pocket carry the Nano in business slacks like I do the R9, but I'm guessing that the Nano would go into regular jeans OK - wouldn't be as easy to retrieve as the R9, or as inconspicuous, or as comfortable but it would be doable. I notice that most shorts now - like your typical Khaki shorts - have generous pockets - larger than jean pockets and the Nano would be fine in those.
My R9 is so small that it isn't snug in the pocket when I wear shorts.
All in all I think the Beretta Nano is a nice little gun.