Just bought a second hand 505 upgraded to 511 with 5 amp transformer for £155 off the bay and must say very pleased. I don't have locos with sound or lights, just basic DCC concepts chips. I hate the cheap plastic feel of some other DCC controllers, Dynamis with all its probs, Gaugemaster 2 so plasticlike TV remote! Love the metal, built to last, real feel ZTC. Don't want my railway computerized with a laptop. Can't see any reason to upgrade.