The Deltang Receiver I'm using in my BPRC engines is rated for 3 amps, with an available daughterboard for an additional 3 amps (which I don't use). So far none of my engines has tripped the polyfuse protection.
While there are places in the states that sell the RX65b, I have gotten mine from RCS Australia and now RCTrains in the UK in about 10 days. The boards from RCTrains can be bought pre-wired so all you have to do is make the connections at the other end (battery, motor, lights).
The BlueRail board is rated at 2 amps. I have had times where my Williams E7 trips the fuse, but not often. The settings can be adjusted to more or less compensate for it from what I've found. Adding a Bluetooth 2" speaker added very little current draw to the circuit and sounds nice.
Once wired up there is no "learning curve". Simply turn the transmitter on then the receiver, set the direction and turn the throttle and off you go.
I've used a conventional transformer, TMCC, and DCS in the past, have not used DCC. BPRC works great for me, no books to read and no wiring to the new layout I'm building.
