By and large, the new iPod is pretty similar to the old one. Apple has changed essentially nothing about the outside of the device, so the way the components all fit together is mostly the same. The one notable change is related to the way the battery is secured in the case: "peel-out adhesive tabs" replace the more persistent adhesive from the fifth-generation model. You still need to heat up the adhesive securing the screen to the back of the case to get inside the Touch in the first place, but this change was enough to bump the new iPod's "repairability score" from a three to a four on iFixit's 10-point scale.
The capacity of the battery changes very little, from 1030 mAh to 1043 mAh. The camera, while a big improvement over the fifth-generation Touch, doesn't look quite as good as the ones in current iPhones. Its lens has an f/2.4 aperture rather than the f/2.2 aperture of the iPhone 5S or 6-series (that's the same as the iPhone 5 and 5C). iFixit also notes that the lens isn't made out of the sapphire crystal used in the iPhones, which means it won't be quite as scratch resistant.