I'm looking for a new portable notebook and really like the rMBP 13. I will be using it in grad school and I do need to run windows excel on it for at least some of my classes...there's some functionality that mac excel unfortunately doesn't have. That aside, I'm torn between a windows ultrabook (all of which seem to have some issue or another) or the MBP. So my questions are: How is windows performance on bootcamp, or is parallels the way to go? Any glitches/bugs I should know about? How is the retina screen in Windows? Between the cost of the mbp, plus having to buy windows and possibly parallels for it, I'm going to be spending about $400 more for the mbp...so am not quite sure at this point.