There are at least four means of controlling locomotives running on track power: DC (local manual control using a power pack), DCC (usually remote, using a hand held throttle that can be wired or wireless), Radio control using on-board throttles, and trackside R/C (remote control of the track voltage).
There are at least three means of controlling locomotive running on battery power: Remote (using radio control), local (using manual controls on the locomotive), autonomous (on-board smarts that make control decisions).
Most indoor railroads are run on track power, as opposed to battery power. But how you control your railroad really depends on what you plan on doing with it. Sit back and watch continuous running? Switching operations? Automation?
You made some very good observations but you left out my favorite both for indoors and outdoors which is standard track power but with the addition of a tethered remote. Not all power supplies allow for this but the LGB Jumbos and Bridgewerks SR-15 are a couple that do.
There are several ways I use tethered remotes including manually using the throttle when I am sitting next to it but I use the tethered remote when I want to run the switch yard (which cannot be reached where the throttle is) or else when I want to walk with the remote throttle to a problem where I can power the loco as I sort out the problem.
The advantage of the LGB Jumbo (yes it is both expensive and discontinued so it may not be the best choice) is that it offers forward and reverse while other tethered remotes may only offer one directional control.
The main reason I like tethered remotes is because (in my experience) they offer a much more precise throttle control. All of my radio controlled remotes have a bit of jerkiness that imply a pulsed (stepped) throttle without continuous full spectrum control.
The two disadvantages of some of my radio control radio control remotes is that they occasionally lose communication with the power supply or if no buttons are pushed they often shut themselves off (to save the batteries) and in both cases I lose control of the train(s).
That said, I freely admit that I seem to be in a very small minority that like tethered remotes.
The majority of indoor railways are HO scale. Those spoiled brats have an endless variety of things to choose from and most mature HO railways are run using track powered DCC. Radio controlled throttles are a nice option. That is what I use on my On30 layout.
DCC in large scale is beginning to grow as new products like the QSI Plug and Play decoder with sound become available. AirWire offer a DCC like operating system and Aristo-Craft are also planning to release one. I believe in time DCC will become the operating system of choice because of the many features it offers such as: speed tables, consists, complete horn and whistle control, independent control of lights, etc.
I have been frustrated with poor radio range and the inability to run a double header without a trailing power car using radio control and battery power outdoors. Consists with DCC systems are no problem as the receivers in each unit will run together without glitching. The lights between the units can also be turned off independently, leaving only the headlights on the end of the consist operating.
Like any full featured product, it can be expensive to purchase all at once. Fortunately you can start with basic track power and add the DCC components as your budget permits. The Plug and Play QSI decoder with sound as an example can be run with basic track power, although the activating the horn and bell with the power supply’s reverse switch is pretty rudimentary. Adding their Quantum Controller solves that problem.
If you will run only one loco at a time in a continuous circle, then traditional track power is fine. Expand that to bidirectional running with two or three trains at a time, and you will need the complexities of cab control. Smaller scales have relieved themselves of cost and hassle of block control by using DCC. And it is a good choice in large scale too if you run multiple locos at a time on an indoor railroad.
Battery RC is good too for multiple train operation but the complications and expense of installation (compared to DCC) is likely best reserved for outside where wiring for multi train ops can really be a pain. Take a look at the trackplan of Fred Mills' Ironwood peter's Pond and Western http://ovgrs.editme.com/TrackPlan ... now imagine wiring that for traditional track power or even DCC for that matter.
Automation is not something I have had experience directly with in the garden but it is possible ... anything from computerized control of the railroad to just the automated movement of a single feature. If this is really what turns your crank then plan accordingly.
For my modest efforts, track power has worked well both inside and out. I'm partial to the Crest/Aristocraft PWC (pulse width control) units. I like the more protoypical momentum and brighter lights at low speed. My LGB engines run fine on it, but I don't run sound so that isn't an issue.
Depends: How big a layout? How many tracks? Do you want to run more than one train at a time?
I run only one train at a time as my layout is small at 10' x 19' so I'm using straight DC, controlled thru a Basic Train Engineer R/C speed controler and using Atlas control switches for block control.
I use the Aristocraft TE indoors and out for RC track controlled power.
I tried a wired power control and did not care for it as it impedes troubleshooting problems. A RC is very helpful in that you can be right next to engines and cars and control the power when looking for problems.
I do fix problems for others so analog controlled track power works for me.
I use both track power and RC for my indoor layout. The track power allows me to run for very long times and while those trains are running I use battery (RC) control on other trains running on the same main line or do switching. This allows me to run a through freight and still a have the local frieght running, or to run passenger and other options at the same time. It works for me but I guess mostly it is up to you.