It is a bit of a mess; documentation often amounting to a few example calls. However, I've written a fairly well received data analysis package for a government department wherein the input and output had to be in excel spreadsheets (-sigh-), using only xlrd and xlwt, alongside numpy and scipy. It's a bit Rubegoldbergian (because.. excel), but I owe a lot to the authors of xlrd and xlwt (they've even supported named regions). So i'll be curious to see how xlwings implements the numerous methods available from xlrd/xlwt.