Show blank instead of zeroes

Hello.

I have a formula: SUMIFS(Sheet1!$D:$D,Sheet1!$B:$B,$A8,Sheet1!$C:$C,O$1)-SUMIFS('Sheet2'!U:U,'Sheet2'!$G:$G,$A8))

I want the result to be shown in all cases, except when it is =0.

Right now I did it this way: IF(SUMIFS(...)=0,"",SUMIFS(...))

But there are probably hundread of such formulas, and even bigger and complex ones, and this file is already working very slowly. Is there an easier and less resourcefull way of doing this?
I read this page: http://office.microsoft.com/en-us/ex...005199879.aspx

But I'm not sure if other ways are less resourcefull. For example I think that I can use Conditional Formatting, but it's not the best option.
The way to turn it off in Excel at all is not an option.