having trouble with Creo vps rip

I have recently been given a VDP project. I am publishing groups of 10-30,0000 text varibles out of Pageflex 11 x 17 duplexed . My rip time on the Creo takes forever when I publish as a pdf. I when I publish as a VPS my rip time is cut in half but the output is terrible. There are white lines running through the document anywhere there is a text box or image box and high res images look jagged and pixaled along the edges.
Has anyone had this issue with optimized rips?
Are there any adjustments that can be made to the rip to fix this?