I have one and my only real complaint is that it reacts with my sweat the way most blued Rugers do...it pits. Not a big issue. For a $248 gun, it has been flawless. Easy to carry, shoots pretty well if a bit snappy. My Shield 45 basically replaced it as I find it easier to shoot, has a bit more thump in caliber, and the finish has not reacted to my sweat. The EC9S has become a reliable little back up. Actually, it's the only 9mm I still own. It's well build with few things to go wrong with it. Magazines are cheap and easy to obtain. It gets the job done and doesn't cost a fortune to do so.
I actually rather like and prefer the single stack guns over the newer ones that jam 10 rounds into the same frame. They just feel better in my hand, balanced maybe? I like the concept of the EC9S enough that I may pick up a Glock 42 or 43 the first part of the year if ammo availability settles out. For now, I'll carry my Shield, but the little EC9S is tucked away in my emergency go-bag with a bit of emergency supplies. Honestly, a light, some money, a way to make fire, a tool, a bit of cord, and a small 9mm with an extra magazine fits in a bag no bigger than one of my wife's summer purses.