How much of a "pull" would indicate a problem with alignment?

For example, my steering wheel feels pretty neutral. I dont have to "hold it" one way or the other with any force to keep the car in the lane, but it will start to slowly drift off center, usually to the right, after about 4-6 seconds of letting go of the steering wheel. It will drift to the left sometimes, too.

Im assuming this indicates the alignment is pretty good, but can comeone back this up or refute it to cure my "New Car Neuroses"?

 

brand new, my car had a tendency to drift left when i let go of the wheel.

after my coilover install and alignment, i now have a tendency to drift right when i let go of the wheel.

go figure...