Compatibility Issues?

I am contemplating buying the latest Mac tower, which I am guessing would require the latest OS and the Cloud version of PhotoShop, etc. Are there any issues regarding file conversions? My typical workflow in PS starts with RGB which I quickly convert to Lab for most editing. I then convert to cmyk for output, either for my inkjet printers or for offset printing. What I am concerned about is any variations behind the scenes from my current system which is CS3 and OS10.6.8. Is there anything I need to be aware of, any "new and improved" features that could screw me up? Dick Busher Cosgrove Editions 7042 20th Place NE Seattle, WA 98115 206-524-6726 888-507-7375 dick@cosgroveweb.com