Update to my last post, thanks to one of the comments.

In addition to the lack of Mac-expected interface features, Excel 2011’s performance is a bit uneven. When you’re scrolling large spreadsheets (either by clicking and holding on a thumb scroller or by drag-scrolling), the sheet feels like it’s moving quite slowly, even on current hardware. In back-to-back comparisons between Excel 2004, 2008, and 2011, the 2011 release was easily the slowest of the three, it took over six times as long to scroll through my test document as did Excel 2004. (Microsoft has told us they slowed the scrolling down due to user complaints about it being too fast. While it may have been too fast in Excel 2004, it’s currently twice as slow as Excel 2008, which seems like an excessive slowdown to me.) When you add in the lag-on-window-resize, the Excel 2011 interface can feel slow at times. (Rob Griffiths at MacWorld via TechWorld)

This is exactly my experience. While I appreciate the increased speed in calculations, (I have noticed this – It’s very quick) in this day and age, I find it simply irresponsible to create a user experience as unfriendly as this.