I think you and I are maybe the last PT hold-outs around here other than EA employees so I'm eager to read how this works out for you. I've got 3 macs at least 10 years old or more that are due for replacement as well & now that my partner is gainfully employed, this might finally be on the list. That being said, upgrading could get very expensive, very quickly as I'd need a new interface to replace the old 002 I've used for like 20 years.
That being said, my partner also eligible for educator's discount so $99 a year wouldn't be the worst option for me if Reaper doesn't work out. The idea of learning a new DAW to the point of achieving a similar comfort level from 25 years of PT use sounds shittier every passing year.