My first Gscale loco was battery r/c - the infamous first generation, battery powered Bachmann 4-6-0. I have never run track-powered.
I then dabbled in Revolution Train Engineer, putting a trackside unit in the tender of my 4-6-2 Aristo Pacific. And a 5495 (?) Onboard RX in an Aristo C-16, which is still running, btw. That must have been early 2000s. The next major conversion was an Accucraft EBT #12, using Soundtraxx Sierra sound and the RCS RX/TX, I think.
After a lot of live steamers, I realized the advantage of the RCS DSM2 protocol as it allows you to use different TX (Spektrum if you like sticks, RCS if you prefer knobs,) and 3rd party receivers. To this day I have not had a bad RX - just ones with bad documentation.
So I converted a few electric locos using RCS TX and DSM2 RX with a Viper ESC supplied by RCS. Many of them use a sound board from MyLocoSound in the UK, which are supported here by G Scale Graphics.
I got a modern Crest Revo 2.4Ghz rig, complete, with Sierra sound, in an estate sale, and it is squeezed in the tender of a Bachmann Spectrum 2-6-0 [not the original tender.] Since then I have used the Revo board in a few instances.
I also tried a Blutooth when it first came out, but the HO boards just shut down when I ran. Finally, I have a WiFi RX board that emulates a regular RX, and I had no problems with that either.
Both these systems used a phone, and I never had the problems of not being able to read the screen, etc.
My opinions? Crest Revolution 2.4Ghz works fine, though the sound options are limited. I’m waiting to try a Blunami 4408 with some power in it, but the price makes me pause.