There are 2 companies I'm trying to get totally away from: Adobe and Microsoft. It looks like Adobe may be easier than Excel makes leaving MS. There's better stuff than Office for everything else but Excel.
Funny, because Excel was the application that brought me into the MS Office fold some 19 years ago as well. Word? Word 2.0 was crap compared to WordPerfect 5.1 (on DOS). But Excel? Man, that just mopped the floor with every other spreadsheet out there (Quattro Pro innovated the multiple tabs thing, but then Excel plagiarized that for their next release as worksheets).
On the other hand, today I use Numbers whenever I can, which is pretty much any time I have something I don't need to send out to Excel users. It's just much more flexible for what I want to do.
For instance, I needed to perform an average on 500 cells in a column; in Excel I started at the top and dragged down for about 10 seconds, until it hit the end of the filled in rows, and 1.5 seconds later I had selected well over 20,000 "rows". In Numbers, that would just be a matter of clicking the column header, and I never hit the "scroll thousands of rows before I can stop the scrolling" because, well, there aren't ever thousands of "empty" cells extending forever in every direction waiting for me to put noncontiguous data in them (unless I tell the table to be that big). Likewise, in Excel that formula reference ends up as "=Average(E7:E539)", while in Numbers, it's "=Average(Duration)". Moving from "your page is one big grid which you can divide up into multiple tables" to "your page can house as many grids as you want, but each grid is one table" is a
very powerful spreadsheet paradigm shift.
That having been said, Numbers today is lacking a LOT of the depth of Excel. I get that. But, since I don't need to use that depth often, I find that Numbers suits my purposes much better.
For me, today, Excel/2008 is equivalent to Lotus123/1991. Numbers will be playing the role of the game-changing paradigm shift. Given what I've seen of Excel 2010 and what I've heard of Excel 2011, MS just doesn't "get it", and will be playing the part of the "slash-commands are far superior to toolbar buttons" luddites for the foreseeable future.