I would definitely recommend getting one or the other. I don't know much about the decimo but from what I understand, it is more or less the same design, thinned out and lightened up a little. Is that right? Either way, you'll end up with a good pen I suspect. When I first saw the VP I wasn't overly fond of it. A fountain pen without a cap seemed odd to me and I figured the clip would always be in the way when sketching. I also wasn't a big fan of the long clicker on it. The pen just looked odd and impractical. However, when my folks gifted me the VP last year and I got it in my hands, it started to grow on me pretty fast. I have found that it requires no real maintenance to keep it flowing, just repeated water flushes between ink changes. The Vac on the other hand seems to need constant fiddling to keep the ink flowing. The VP is definitely my fave at the mo. It always works and there is no cap to be constantly dropping (I don't like working with a posted cap). I haven't found the clip to be in the way and the looks of it have grown on me. I love the yellow, kinda retro-y in such a newfangled design.