The clasp area is quite thick. For those with the original band, the battery/galvanic sensor without the clasp is about the same thickness as the original Band's heart rate sensor PLUS the clasp. Honestly, with the improvements to the size of every other part of the Band 2, it's a livable compromise... under the assumption that you will use the band face-down. If you intend to wear the band face-up and you type a lot, you might want to reconsider it. Overall, my opinion is that the gaps between the edges of the flat display of the original Band and my wrists were more noticeable and ugly than the thick clasp of the Band 2.
One more thing that Dan Rubino mentioned in his Band 2 review that I've found to be true in just the first few hours of owning the device is that the surgical steel connector for the clasp gets scuffed pretty easily by the clasp itself. I have a few barely-perceptible scratches on the back of the clasp too. I don't care much about the connector scuffing; it's going to be hidden by the clasp, but I'm not looking forward to a completely scuffed clasp in a few months.
Overall, it's a huge improvement over the Band 1 in every physical way except the points above.