So far, so ordinary. What makes them different is mainly twofold. Firstly the equipment was developed as a means to control locomotives on a particular railway, namely the portable and highly-popular 16mm layout 'Timpdon Lake', a veteran of exhibitions in the North-West (and further afield) for more than ten years. The system was therefore purpose-designed for the job. Secondly the transmitters operate at 433MHz, which is a good few kilocycles below the current crop of 2.4GHz units almost universally used to control trains, boats and planes, and cars. As to why this is much better I hesitate to say, mainly because I don't really know. I can however point you in the direction of a Technical Note, should you really wish to discover for yourself.
The multi-channel transmitter also creates a significant operational advantage, in that it is much easier for one person to control two or more locos at (more or less) the same time. A train can be parked in a passing loop and control changed to another which then drives past it. The sort of thing that smaller-scale train drivers have been doing since Frank Hornby was a lad, but is fairly rare in garden scales. It is also possible to specify that a train will continue running once control has been changed to another, the default being that it comes to a halt after ten seconds. Most operators using conventional equipment only drive one train at a time, no doubt because holding two bulky transmitters simultaneously not only strains the wrists but also leaves no spare hand for the G&T.
If there is one downside, it's not a particularly cheap system, although having the multi-loco transmitter option is quite a money-saver. It seems a straight choice between something mass-produced in China for model aircraft and a well-engineered UK-made specialist model railway product. For many there is no argument, preferring to spend their limited resources on rolling stock and track rather than on smartypants controllers. However this particular modeller is gradually (and some would say at his age, about time) realising that quality is sometimes worth paying a bit more for.