I need a mat upgrade so I've been reading all the innovative diy mat posts. The projects I've seen have the soft insert underneath the foam mat. But I noticed on the Truestrike site their mats are constructed with the soft gel on top of the foam, then a thin protective turf over that. Has anyone here tried to duplicate that approach? Also, has anyone tried using memory foam instead of gel? Memory foam has a nice bounce back but could be too squishy.