Source: We've developed a business app for Win 8, development was co-sponsered by MS and Intel. We have a very succesful iPad app in our vertical, it allowed large swaths of our customer base to switch to iPads for their fieldforce.
MS themselves acknowledged that if you want to handle "large Excel" files, the RT is the wrong device.
The Surface Pro 2 finally has the performance.
I understand your enthusiasm, switching from a 2005 MB Pro to any device in 2013 is mindblowing. Just hold back with a little bit too much hyperbole, the RT was an underspecced consumer device, Office support on it was an afterthought and a paniced scramble for the dev team (as documented here on HN a while ago).