This is not the case. The PWR-75 is the power supply if you choose to use it. Because it is also controlled with wireless signals (on/off and real-time status) from the HC-1, it can also act as a "repeater"...basically it means that commands originating from the HC-1 can go directly to the loco, and also can be routed through the PWR-75 at the same time. It allows each command to have two paths of travel, so that there is no chance of a signal getting lost. The PWR-75 is NOT needed for the R/C to work. The only thing needed is the HC-1 controller and a Railpro equipped loco.I've just been looking at the Railpro site and it would seem that the power pack, PWR-75 is also the base station for the R/C, which means of course that the whole system relies on this unit to power everything, both track and R/C, and as there is no mention of the input voltage (as far as I can see) it will most likely be built to suit US standards.
It's also important to clarify that DCC locos and Railpro locos will not run together in a consist. They will run just fine on the same layout, but cannot be used together in a consist. The DCC locos will not respond to Railpro and Railpro does not respond to DCC. Railpro only uses the power from the tracks that DCC provides, not the command signals. I run my Railpro equipment on the club DCC layout and have had no issues.
I have used Railpro for a year now and am very happy with it. I used DCC before that, and although it was pretty good I absolutely hated trying to speed-match locos. I would tinker around and change settings for hours and finally get two locos running well in one direction, only to flip them around and realize they weren't matched in the other. It was extremely frustrating. That was my main motivation to pick up Railpro. As stated earlier in the thread, consisting with Railpro is as easy as setting a single variable for each loco, then the system automatically takes care of the rest. I can consist any loco, from any manufacturer, in any direction with a few taps of my finger. So much easier. The speed control with Railpro is impressive. The throttle knob is very responsive and can very easily be adjusted to individual 0.1 speed steps.
The sound library is somewhat limited at the moment but is expanding. The sounds that they do have are very nice. The GE FDL16 and the EMD 710 are the best I've heard. The 645 Turbo could use a bit of tweaking but it's not bad. The horn selection needs some fleshing out. Tim at Ring Engineering is open to people submitting their own sound files (good recordings) that were made by themselves and are willing to have distributed. He can then work with them and convert them to Railpro format for download. The sound library will expand, but right now much of their focus is on producing hardware and getting the basic line-up of equipment situated.
Customer service is the best I've dealt with. Tim goes above and beyond to take care of his customers and answers questions very quickly. I highly recommend Railpro to anyone interested in trying a new system. It is very impressive and works very well.