Yeah I actually like the EU cases even better than the US ones. They are easily and cheaply available in the EU and fit those thicker EU games manuals much better than the thin US DS cases.
I agree. I tried modding a US case for Game Boy, but it seemed like such a hassle to have to do it for every case, where with EU cases I could just clip two tabs and it fit perfectly. I don't mind the extra space, since I don't have THAT many games, and honestly ANY case takes up more space than loose cartridges, so I was okay with that. Plus as a bonus it holds my Game Gear and even Virtual Boy games nicely, and it's clear so it matches my UGCs. Most spines weren't that hard to modify since most games have a single color background and the logo, so I could re-size without stretching. Shipping was a little pricey, but to me it's worth it for the convenience.