Clifford - Welcome to the forum and thanks for the question.
I don't know much about Bluerail besides what I've read on various posts, so my information may be incorrect. From what I understand Bluerail is a bluetooth-controlled module that you can install into a locomotive (not sure if it needs DCC already installed or not....probably not). It can be controlled from your smartphone. So touchscreen control and wireless communication. In those respects it is similar to Railpro. Same concept, different implementation.
Bluerail does talk about two-way communication, but I haven't heard what that actually means in their application. How will they use it? Not sure. Railpro uses two-way communication to automatically load share, as well as to provide real-time feedback on the status of the locomotives, and real-time adjusting of settings. I'm presuming that Bluerail will be capable of the something similar if it is truly two-way communication. Whether or not it currently has that functionality is another question.
The current Bluerail module very large. It seems that at this point it can only be used in tenders of steam locomotives or F-units. No doubt they will decrease in size over time. Railpro is currently on its second generation and their LM-2S can fit most any HO locomotive. I'm currently installing them in SW-1200's.
I don't think Bluerail has sound, though I assume that's in the works. Railpro currently is fully sound supported, though there is room for improvement in some of the prime mover files. I know that is currently being worked on.
If you were ask me personally, I am familiar with and like Railpro. I have no hands-on experience with Bluerail, but I don't need to. Railpro has made running model trains fun and it does everything I need it do to and more. Bluerail will probably get to the point that Railpro is at eventually. At that time I would hope that Railpro has advanced even further. Bottom line is that both control systems are FAR better than DCC.
-Kevin