It looks like those in European nations will soon be able to buy a Galaxy S4 that's as fast and quick as all the recent Android flagships, including Samsung's own Galaxy Note 3, as the Snapdragon 800-powered Galaxy S4 has made its way to Europe, ending its South Korean exclusivity. The upgraded variant comes with four processor cores clocked at 2.3GHz and also supports LTE-A connectivity (up to 150mbps), though the latter is something that's not yet available almost anywhere in the world.
The device doesn't seem to be up for sale on any retail or online store right now, but it has been listed on Samsung Germany's website with White Frost and Black Mist color options, so it shouldn't be long before you're able to buy one. It should be a great option if you're looking to buy a new Samsung device with top-of-the-line specs but aren't comfortable with the Note 3's big screen, nor want to settle for the original Galaxy S4.
Oh, and by the way, if you're looking for a Snapdragon 800-powered device with water and dust-resistance, then you might want to wait for the Galaxy S4 Active that is also rumored to be getting the processor upgrade.