I picked a month subscription of office 365 (I know I shouldn't have) to test out Excel. I've only been playing with excel (on the iPad) for a couple of hours, so I know I haven't really delved deep into the details. I have a number of spreadsheets that I use for my personal life, there's also a lot of spreadsheets I use for work. I had the personal stuff in numbers, so I can sync them on my Mac and iPad. I will say that I liked numbers up until they "upgraded" it and removed much of the features the only thing that kept me using it, was the fact that it so easily synced with my Mac and iPad. In comparing the two, I found the general UI of Excel to be superior, the ease to which I could enter formulas was night and day compared to Numbers. The depth of formatting and available formulas is also in Excel's favor. Overall, I think MS did a great job in rolling this out. Where it falls down is the subscription model. Do I really want to pay 100 a year? In all honesty I really don't but if apple fails to improve numbers I may not have too much of a choice. This also allows me to use a single product for both my work stuff and my personal stuff.