One really obvious point - check you haven't gone from a knots aeroplane to a mph aeroplane.
But if everything's still in knots, then yes, the correct approach speed for a -161 is 63kn, reducing with weight - so a half tank solo aeroplane, likely to be around 80% MTOW, will want about 57 knots. I can think of no good reason to fly a 70kn approach in a -161 with flaps used as per the POH.
BUT, I have also seen various instructors around the world use 70+kn flapped approaches, causing some combination of hard landing and float. It's bad practice, poor airmanship, and it's just as well that PA28s have such strong nosegear !
I think that the "going to the airlines" argument is spurious - all pilots should learn to fly the aeroplane that they're sat in, properly. Not the one after the one after that !
G