I reviewed the RailBoss 4 for Garden Railways when it came out 6 years or so ago. G Scale Graphics has it linked on their web site. It’s not as full-featured as other systems in terms of lighting and sound control, but it’s also the only system on the market that allows for automation in the battery R/C world. I’ve seen the automation in action on Del Tapparo’s railroad, and it’s cool. (Del owns G Scale Graphics/Railboss.) I simulated the automation features for my review, and they were fun to set up. If you’re going to be building a railroad where you want a lot of automation (back and forth, station stops, etc.) this will do it without the need for track power. The RailBoss system will interface with the Phoenix sound system and their automatic uncoupler. Note that this review is 6 years old, and the board and software has been updated since then. We also use the Trackside RailBoss 4 system out at the Colorado Railroad Museum. It doesn’t have the sound controls, but the operation is similar. The trackside system does not allow for automation.
My personal “gripe” with this system is the key fob controller. I personally prefer a graphic display or some visual indicator of speed and direction to be on the handheld control. Some would say, “well, you can see the loco moving on the railroad–isn’t that enough?” Not really, no. I do a lot of prototypical operation, which means a lot of back and forth. There’s a lot of time when the train is not moving but there’s still low voltage going to the motor. That prevents you from changing the direction. If you don’t have directional lights on your loco, you don’t know which way it’s going to move when you increase the throttle. (In the steam era, trains often ran without illuminated headlights in the daytime.) It’s also very small, and very dark. That makes it easy to misplace outdoors. Set it down, and it vanishes into the garden. The key fob controllers we use at the museum are attached to 3" x 10" bright yellow pieces of plastic. You can also attach it to a lanyard and hang it around your neck. (I’d recommend bright yellow for the lanyard for the same reasons–easy to see when you set it down.) If you’re running multiple locos, then you’re going to need multiple key fobs. Keeping the organized may present some challenges. I used to use the old RCS control system in the 80s and 90s. It was very similar–one remote per locomotive, and you only had pushbuttons on the controller. The advantages of being able to control multiple locos independently from one transmitter are enormous.
You already mentioned not being able to control switches remotely with the RailBoss system. Pneumatics, perhaps? (I’m not a fan of automatic switches outdoors anyway. Too easy for ballast, twigs, or bugs to get caught in the points and keep them from closing. I’ve just come to being used to flipping the switches manually and making darned sure they’re closed.) Having said that, manual switches do not play into complex automatic operations, so you may need to look at a parallel system, perhaps using magnets on the loco to trigger switch machines.
The Airwire system gives you access to the world of DCC decoders, but it’s at the expense of being able to do any kind of automation.* I put the asterisk there because there are decoders which allow for some level of automation within the decoder programming itself. (Lenz and Zimo offer this, others may as well.) What I do not know is whether that can be triggered via something like track magnets or whether it’s strictly controlled by changes in the voltage going to the decoder (DC or asymmetrical DCC). You’d have to do some digging around. Dan Pierce is the Zimo guy around here, and Stan Ames knows the Lenz stuff backwards and forwards. They’d be good folks to ask. With the Airwire, you could control the switches via the handheld remote (see above caveat about automatic switches outdoors). Again, though, with the automation, you’d probably need some kind of magnet on the locomotive to trigger switch events. DCC BitSwitch has a lot of automation products. I don’t know if they’re still in production or not, nor if they can be adapted to the battery R/C environment. (Their web site has gone dark, but Tony’s Trains still lists their products for sale.)
The negative with Airwire would have to be the reliable range of the transmitters. If you’re routinely going to be within 30’ of your trains at all times, then you’ll be fine. If you’re going to have a large railroad spread out over hundreds of feet, but want to run it from the comfort of your deck, then there will be places where the locomotive will likely be out of range. My back yard is 30’ x 65’, so I’m never that far away from my locomotives. My dad’s railroad takes up a space around 100’ x 200’. I cannot reliably sit in any one spot and know I’ve got control of the loco no matter where it is on the railroad. Since we do prototypical operations on that railroad, we’re always near our locos, so it’s not an issue.
In terms of installation, there’s virtually no difference between the two systems. If you’ve done LocoLinc, then you won’t have any troubles with either of these systems.