If even just removing and refitting your original struts and springs then the entire geometry requires a cursory check for any misalignment.
Fitting lower, uprated springs and dampers is a definite geometry reset
With regards to it feeling better?
That all depends if you can live with the harshness, the following of ruts in the road and hopping under heavy braking that comes with uprated suspension.
You would see just as dramatic improvement with new standard shocks and springs given how bad the handling was anyway... It's a common misconception that uprated dampers and springs are an essential requirement. Look at it this way... No owner complains about the way an Alfa handles when brand new from the factory do they?
That's why we buy them or we would hand the keys back after the test drive
If you had a goosed shock absorber on the rear then that would have dramatically affected the handling not just on the rear but even more so on the front. Imagine driving without one rear wheel fitted. That's the same effect as the opposing front suspension lifts, losing contact with the road surface while going light and heavy as the rear is dipping and bouncing all the time with no resistance to the rear spring rebound offered.
It's no wonder the handling is bad.
Alfa's in particular are very sensitive to any shock absorber failure due to the nature of independent rear and double wishbone front set up.
40mm drop at the front and 30mm rear seems a bit unusual to me as the 147 has a naturally raised rear end already... It will look even more pronounced with a ten mm difference added, like a big lady picking up a penny... Imho it should be a standard drop all round to preserve the natural balance the car had from the factory.
Horses for courses though I suppose.
Bring back Tapatalk !!!