What a fun flying machine!
I did my complex in an M20J after doing my private training in the 172, so my experience was very similar to what you might have.
The Mooney will taking some getting used to and it will be much easier after the very first time you approach an airport and realize you're too fast and can't get it to slow down! There isn't a whole lot of drag on the thing -- narrow fuselage, flush rivets, and more. If you do a brief 60 degree bank somewhere near entering the pattern that could help you drop some speed.
I like how the yellow arc doesn't start until 176 knots! I remember going into HPN one night during my instrument training and NY approach asked us for our indicated airspeed. I replied "180." He then said, "Northwest ### slow to 180 for spacing into White Plains, you're number two behind a Mooney."
It is loud -- have a good headseat and consider earplugs and ANR!
Don't get it into a spin. The man who I did my CFI lessons with was a test pilot for his whole career and did GA stuff. A friend of his bailed out of a Mooney after realizing the thing would not recover from the spin. As he put it, "If you spin this airplane and don't bend metal, the manufacturer would like to know how you did it."
Easiest plane to land I've come across so far.
The prop is 9 inches above the pavement. One bounce, two bounces, propstrike. If you bounce twice on landing GO AROUND.
Have fun flying this thing! You will love it! And you'll forever appreciate those unique Mooney tails when you see 'em on a ramp.