Customers most agreed on the following attributes:
The Giottos MH-1000 is functioning perfectly, for my purposes. Currently using it with 500mm long lens. So far, so good.
This is a well made ballhead. It is my first, so I can't compare to models costing 2 or three times as much. It does everything I expected. For me, it is better than the panhead which came with my tripod and is more useful.
Coupled to a set of Manfrotto 3021 legs, this is a rock solid platform for a Canon 30D with a 70-200 zoom attached. Silky smooth operation but locks up tight when needed.
I was very concerned about the quality because it is so inexpensive when compared to other heads. My concerns drifted away after a few sessions in the field.
despite being one of the cheaper ball heads i find this unit to be very solidly built with positive locking and smooth panning. i expect this to last indefinitely.
the quick release works well to lock down my D200.
my only complaint would be that the levels are not very high quality. but anyone who needs these would probably have a hot shoe mount level anyway.