Here’s my two cents…
I started out with track power, because it was simple, cheap and easy – and also because I had a distrust of batteries, due to problems I’d had with certain electronics (video camcorders, for instance).
Also, I knew that it would be easier to switch from track to battery, if I wanted to, than to go the other way.
Despite living in a very idyllic climate, the track still needed cleaning a lot more frequently than I’d expected. It might have been easier if I’d ever gotten around to building a track cleaning car, but even then I’d still have to clean the track manually after extended periods of non-use.
I have lots of tunnels, and having to open these up frequently for track cleaning was not fun.
In 2012 I scratchbuilt a railbus. Due to the light weight and short wheelbase, it had to be battery powered. I soon found myself running the railbus more than the trains, because it was always ready to run and no need to clean the track first. That convinced me to take the plunge into battery power.
I had been putting off installing an r/c receiver in my 4-6-0, so while I did that I also converted it for batteries. It got a large block of lithium ion batteries that literally let me run it for days, several hours at a time, before needing a recharge. I haven’t yet gotten around to converting my RS3, but it’s next on the list.
The railbus uses the electronics from a small r/c car. The locos use Aristo’s Revolution control system and are fitted with Phoenix sound.
So far I haven’t gotten into switching, etc. Mostly just let it run. But the r/c control is indispensable even for this, mainly due to the ability to stop and start the train, or adjust the speed, from a distance. And it’s essential for running two things at the same time, such as the train and the railbus, to avoid collisions.