Since: Dec 04, 2007
Honestly, I've never heard of Memorymoon as a brand, so I can't really offer any info or opinions on them.
I'm assuming the CS-80V is Arturia? Now them, I've heard of, and I think they generally make pretty good sounding plug-ins, and some of their hardware is kinda cool too, like the Mini/micro-brutes and the upcoming newer version of their beatstep sequencer. So, I usually stick with what I know, and that would probably be Arturia.
Also, I can't tell you which one is really more preferable. That is for you to decide, so go listen to some examples of both plug-ins, and whichever plug sounds better, or more authentic, go with that.
Just be aware, the Arturia demo songs use minimal processing so you hear the pure synth at work, whereas the soundcloud tracks on Memorymoon seem to be more complete, which includes effects processing, so you're not hearing as much of the pure plug-in quality. It's just something to be aware of.
Also, it wouldn't hurt to try the demo versions. Both plug-ins have a demo download, so try those out, and see which one jives with you the best.