I have one,, and I'll admit I haven't even shot it. Mine is hammerless.
But I do have a few other gun similar.
I own a Speed-Six in 9mm, a S&W 464 in .40 S&W, a GP-100 in 10mm, a S&W in 45 acp. All use moons or 1/2 moons.
I also own a LCR in 38 spl.
I have carried it & shot it. I use a slop holster in my pocket. The 9mm will fit that holster as well.
Moon clips are NOT an issue with me. Some folks feel they are not a good way to carry spare ammo, or are a PIA etc. Heck,, I USED to be kinda like that. Until I figured out I was wrong.
I have a lot of Ranch Products moon clips & find them to be quite good,, and reasonable to purchase.
As for loading & unloading the moons with ammo or the brass,, it can be hard OR easy.
I use a moon clip loading tool,, (about $30-$50) and it's well worth the expense in my opinion. Makes it very easy to load the ammo into the moons. I made my own de-mooning tool. Quite simple. A metal tube, that the brass can slide in, about 10" long, with a handle, and a notch cut in the face of the tube. I made mine (I have 3 of them) out of an old golf ball retrieval shaft. I took the handle end, cut it off where I had about a 10" handle. Then I used a dremel & cut a small notch section. (If someone needs pictures, I can take them, or they can look online at the same type of tool you buy for it.) It makes de-mooning the brass easy.
For reloading a revolver,, it's darned fast for sure.
As for the differences in 9mm vs. 38 spl,,,, well,,, there is enough ballistic data out there for anybody to study & make their own decisions as to what THEY prefer.
A 9mm has an advantage in the quantities now available for inexpensive shooting.