Can somebody summarize the difference between these two receivers? I will be using them with my 18MZ on Vbar and Hc3sx equipped helis. I'm new to Futaba S-Bus terminalogy so a little help would be appreciated. If I won't be using telemetry, is R6303SB the most logical receiver to use due to its compact size? I feel like being able to see the main pack voltage is a nice feature to use with the telemetry enabled receivers. Thanks for the help.