I've had Parallels 8 installed on my Macbook Pro for 2 years now, with windows 8.1. I rarely need to use windows EXCEPT that at least once a year for about a month I do a major project involving Microsoft Access and there's no Mac alternative. Most of the reviews I've been able to find look at how well windows performs under Parallels or its competitors or boot camp. I'm concerned about the impact of Parallels on OSX. When I don't have a windows program open is Parallels still using a lot of resources? Is it slowing down the OSX side of things? I'm asking because I need to decide if I should update to Parallels 10 or switch to Boot Camp. I could spend the $50 on Parallels 10 and continue to use Word and Excel when I need those programs, or switch to bootcamp and buy a word processor and a spreadsheet.