Should I keep my shield as-is or try for something else (not much NX left)

I'm a Hero.

My shield gives 21% crit, 30% def ignore.

I'm playing EMS so we don't have the Leafre Set, so the PDR is importantish.

Outside my shield I have 50% boss.

I don't have a huge amount of NX (maybe 22 more scubes) to play with so I dunno if I should risk it.