Yeah, it's a matter of choice really, i went to prime because when I was using orthos i had a quad, in those days (dunno if it has changed though) you had to run two instances and set the core affinity in Task manager so it would stress all for cores whereas Prime95 from v25.5 onward has been optimised to do it automatically, I never went back to Orthos after that.
memtest is good for finding faulty sticks but i don't think I could be bothered booting to it to test a memory oc tbh