I upgraded to Stargazer years ago. It was well worth the money. I usually set up my slalom course and cahlibrate the speed then use GPS Slalom mode. The pull is always within .02 on time. And, I only need a magnet at each gate. It is also useful when free skiing because the GPS will keep the speed consistent without having to use RPM mode.
I don't understand the puck discussion. I know you can buy parts and pieces but really so long as you already have the 3 line display you are just buying the control module and antenna.
Also, there is a new software upgrade that allows you to map your slalom course so you don't need any magnets. Pretty handy, especially if you ski the same course all of the time.