Comparisons to the Nissan Juke are natural, but the Hyundai Veloster is more of a car than a crossover. It's lower-slung, longer and a bit wider. It's sure to be controversial as well, but I'll go out on a limb and say that its styling has broader appeal.
Despite its lower stance, the Veloster has interior dimensions that are similar to the Juke's. I found the headroom to be more than workable in the front seat. In the two-seat backseat, however, the liftgate attaches so far forward on the roof that the rear window is directly above the passengers' heads. This actually gives me enough room, but the ceiling dips down a bit in front of that position and is ready and able to clobber you on the way in or out.
For what it's worth, the single rear door opens pretty wide and is easier to get through than I expected. Legroom comes only at the mercy of front-seat occupants, similar to the Juke.
I like the interior design, which is consistent with the exterior styling. The materials quality is pretty good, but if you're a stickler for soft-touch surfaces, the Veloster will disappoint you. If you can keep your hands to yourself, you'll probably concur that they look fine.
I dislike the cargo access. The rear bumper is exceptionally high, and the opening between the taillights is quite narrow. Being able to raise the liftgate high helps, but still it's more like loading a very tall trunk than a hatchback.