In short, yes, it's worth it.
Night sticks aren't even necessary, although they can be useful. Say you're a human cleric with a +2 Cha. You already have 5 turn attempts. There are items in the DMG that can grab you the other ones you need. Or a quick Cha boosting spell can get you what you need to persist that one spell. That's without Extra turning (which, since you don't need a lot of feats, usually, you can take many times).
Now if you're not human, flaws aren't allowed, and any item you may want/need will be banned, then obviously DMM Persist may not be the option for you. It also might not be want you want flavor-wise. DMM Quicken is much easier to get and more cost effective, too.