You asked for an opinion. I know the truth hurts. The 3,1 is becoming slow. It's fastest in Windows 10. I have one in my closet with a GTX 1060 that is Windows only and it's a much better and more relevant machine now. And I had a Mac Pro 3,1 since brand new and sold it for a 5,1 that royally spanks it up to Mt Fuji. The fact that you were on a PowerMac G5 (slow) to this point must have set a new world record. Had one of those, too. Deal with the answer. Or don't ask. And no, Windows 10 is not inferior to Windows 7. Lay off the crack pipe. Or enjoy obsolete hardware and an obsolete OS. Btw, h98 gave you a good pointer. Get an SSD and use the spinner for storage. All OSs, including El Capitan, will show an obvious increase. Windows 10 is superior to el capitan on a 3,1 in 2017. And privacy violations? How about never receiving security patches anymore? And yes, I know PPCs very well. Used to overclock them. Rev B G4s for the win. Now they are nuclear reactors that belong in a museum.