I'm really enjoying the powerful abilities of Smartsheet, and especially the ways in which it's more flexible than Excel. I have to say, though, it's getting more difficult to accept that formulas just can't reference data from other sheets. This is particularly frustrating when you consider the powerful functions that become less useful when limited to local sheet data.
Take the WORKDAY function, for example. It's great that you can specify a holiday_range for customized. This is potentially extremely useful for managing schedules across teams and a whole company... until you realize that you have to add your list of holidays to every single sheet that uses it. (Why not just have a separate Holiday sheet and reference that range of dates from the multiple other sheets that will use it?)
There's the same difficulty for other functions like INDEX, LOOKUP, MATCH, etc. (I'm sure other users have countless examples, too!)
Smartsheet team, please let us use your excellent formula functions to their fullest potential! Save us the trouble of duplicating cell data (human error!) and piling on hidden cells in places where they don't belong. Let us reference cell data in different sheets!