I have Dell Precision M2800 (i5-4210M 2,6 GHz, 8GB RAM, AMD FirePro W4170m) Should I upgrade my Windows 7 Professional 64 to Windows 10 ?
That is up to you. Personally, I like windows 10 so far. It combines Windows 7 and Windows 8.1. It also will have some Great Added features. If you choose to and do not like it you can always go back to Windows 7. Eventually, windows 7 will EOL so in my opinion I like to be caught up with the technology curve.