The EC9s I just picked up yesterday is also a great shooter, too.
The integral sights were fine and it groups well at 20 - 25 feet. On the first mag, I put 3 of 7 in a one inch center at 20 feet.
It had flawless performance for 100 rounds of fmj.
Of the two, I like the LC9s better. The slide is actually bevelled a bit more so it weighs .5 oz less than the EC9s. I also thought the spray-on Stainless finish on the EC9s was a bit cheap-looking, and prefer the blueing on the LC9s. However, they are pretty much identical in how they shoot, even thought the LC9s has the better sights. It just doesn't matter at close range.
The downside to these smaller pistols is that they are tiring to use after 30-40 rounds. These aren't range guns, but seem well purposed for EDC.
That said, I wish the range officer would let me fire both at the same time in each hand