Haven't gotten on both but they're pretty different skis. The 100EIGHT is a very directional ski (-11 mount point, minimal tail rocker) while the Meridian is much more freestyle oriented. Telling us what skis you've liked before, where and how you ski, weight & height might help.
If you haven't already, I'd take a look at these:
http://blistergearreview.com/gear-reviews/2016-2017-moment-meridian
http://blistergearreview.com/gear-reviews/2016-2017-volkl-100eight