Office 365 is actually pretty good. I wouldn't run a Monte Carlo analysis on it, but Word and PowerPoint are pretty good and Excel works for simple spreadsheets.
They are ok but do not live up to the desktop versions - its not really the individual apps that are the problem anyway. Its how the system communicates, how apps work together that really kill the work flow. I've tried and tried over the years to make it work even just for my basic university work, but its just not worth the hassle half the time.