Howdy and welcome from Austin!
I don't run the hidden antenna but I did a stage 2 upgrade this past spring and am very pleased. Guess it depends on what you want out of your engine, but I chose mostly HD stuff, SE 255 cams, the HD K&N air filter and a Power Commander V. Dynoed 86 hp and 107 lbs tq. Great mid range power surge!
2003 HD Softail Deuce 87k miles and counting
2011 HD FLTRU 40k miles and counting