[SoftwareBug2.0]

One other way that you could classify pickup systems is by whether they handle more than one of the item in the same part at the same time or if they must be dealt with in a sequence. This is orthagonol to whether they're dealt with continously or in a batch.

I agree the previous posters that continous is usually better. I am especially inclined to agree with Joe G.'s reasoning that they're easier to control. Often it's trivial: just turn it on and let it run.