Mine was a topsider. Had to be 30-45 minutes with hot oil, lots of pumping, no vacuum leaks.
I got some other small one that Inlike a lot but have never used it for oil changes. Just atf and psf.
Yeesh! I wouldn't be happy with that.
I can do a complete out and in of a 5er in under 15 minutes with a manual mityvac.
Pump it 20 times or so then walk away.
I'd like a pressure driven one that reverses, but Ive got too much stuff as it is.