I like the original Amaranth but yeah, it's ultimately a fairly generic pop-metal track. M&S version has more heart and soul in it. Also the vocalist sounds like she'd fit right onto a Nightwish album, which obviously helps.
Swim is really nice, but I did notice for some reason the singer mispronounced 'seduction' as 'seducion', which is weird as Anders didn't mispronounce it on the original track. Really minor quibble though. It's cool that their version includes the full lyrics on the 'etched on a crystal display' line, whereas in the original Anders doesn't pronounce 'crystal' for some reason, or pronounces it badly, as I always just hear 'etched on a display'.
When you hear cool new twists on the Clayman stuff it's a reminder of how shit and uninspired the Clayman rerecordings/remasters were. So many cool little things you can do with those songs to give them a new dimension, but instead we just got crappy cover versions that sounded worse than the originals for the rerecordings, and barely any noticeable difference on the remasters. I mean, acoustic version feat. Anders would have been fucking dreadful as Anders can't sing, but Bjorn could have done some nice acoustic renderings of the classic songs to give us something new and interesting. They just didn't care enough.