I got an NN4 with the adapter for my 5DII with battery grip.

I have no problem stitching panos...in fact, everything is going good so far but...I do have a question:

How important is it to get "center bubble" perfectly around the rotation of the head?

I have a pretty beefy tripod; a Vanguard 463AT with a GH-200 head, and when the tripod shows level, the NN4 still show's things to be off. I thought maybe that the "ball" part of it was the weak link so I attached the NN4 directly to the tripod legs but that didn't change anything significantly.

When I level the NN4 and spin it in a circle, the bubble wanders. I can tell that there is play in the whole apparatus just due to manufacturing tolerances...it can't be avoided, so my camera sags a slight bit.

I'm wondering if I'm just not getting an accurate "center bubble" to start with, and was wondering if an EZ-Leveler would be something I'd need or if a slight bubble wander is not that big of a deal.

The lens I'm using is a 14mm Rokinon, not a huge lens at all.