Am curious to know what you can't do with Excel on the iPad that you need to do?
Excel on the iPad is extremely inefficient and also lacks the same abilities as the desktop.
I think trying to use the iPad for productivity as it stands now is counter intuitive in regards to efficiency. The iPad is purely a convenience factor at the moment for the majority of its users when it comes to productivity. Using the iPad satisfies the user because it is small, it is light, and it is possibly the future. It's a dopamine hit, something that allows you to leave the clunky MacBook at home. That is where it ends though.
Anyone who is trying to argue different is in my eyes trying far too hard to justify the purchase to themselves.
So many of you are trying to force a square shape into a round hole and talk yourselves into believing its fine.
You want to consume, ok great iPad's are awesome. You want to try and talk me into believing it's meant for work as it stands right now aside from communicating...save your breath.