The way suspension Springs are engineered at the factory is to take the weight of the vehicle, plus passengers and luggage over the available suspension travel. So for eg lets say 2tonne over 200mm factory. If you chop the springs you are effectively reducing the weight those springs can handle and also making it a shorter distance. This causes premature suspension component failure and extremely poor handling. As far as I know chopped springs are illegal because of this even if theyre still captive. If you wanna slam your car it costs about $100 to get your existing springs compressed. By compressing the springs your car will still be capable of handling the correct weight etc and will handle a lot more nicely. You will almost certainly need shortened shocks aswell.
At the end of the day you do what you want to do. Its just good to make your decision based on fact.