XML table vs Array

What would the performance hit would be for using a table request versus an array for large data sets? Obviously, it would depend on the size of the data set, but I am not looking for hard numbers. I would just like a suggestion from someone who has used the widget with a data set consisting of possibly 100 rows x 30 columns. I would like to create a calendar like view using the widget with up to five characters in each cell.

Also, has anyone figured out a way to select a single cell?

My guess - using XML data model is ~ 30% hit on total refresh time (simple XPath, no formatting). Just a guess though. If anyone has real numbers I would also be very interested to know.

Thanks for your quick reply Alex :).