Well, I have some of everything!
I have quite a few TrainTech coach lighting units. I tend to use them for coaches that have no built-in support for interior lighting, such as my Harry Potter train, some Märklin/Tillig Eastern European coaches (eg 42982), and a Dutch train I have of Artitec coaches. The TrainTech units work very well, and the only criticisms I have of them are that the light is a bit dim, and of course, by design, the lighting is not switchable. My layout is completely computer controlled, and I prefer the train lighting to be switched on before the train starts moving, and before the platform announcements, or guard's whistle sound, etc. So almost all my trains have Digital decoders, and often relays, to turn lighting on and off.
In general, with my collector's mentality, I prefer the Märklin trains to have lighting that is contemporary with the manufacture or design of the models. So I tend to fit original lighting units, with bulbs rather than LEDs, in older models. I prefer the nostalgic effect and colour-temperature of the bulbs. Similarly, when I upgrade an older Märklin loco, I don't change the light bulbs for LEDs, as it spoils the look of the loco for me.
I have quite a large stock of old Märklin lighting sets, probably some of all of the ones made, and I use these for old trains, but fitted with decoders for switching the lights on and off. I tend to use Tams FD-R Basic decoders, as they are tiny and work very well. And I use tiny 1-Amp relays if necessary, which can switch the lighting for a whole train.
But I do fit LED lighting sets sometimes too. I have quite a lot of the Märklin ones (73400 and 73401), but my favourites are Tams WIB-33.2, which sadly don't seem to be in production at the moment. They have all kinds of features and have a built-in decoder that can also switch accessories like tail lights, control-cab lights or lights in other coaches. This unit allows individual control of each LED, variable brightness, effects like fluorescent tube emulation, flickering to show a faulty fluorescent tube, light-sensitive feature so that the lighting can be turned on automatically at night, or turned off in a shadow station, and so on.
I like the Tams products a lot, and they are a very nice family firm. I meet Cornelia Tams at train shows in Germany (such as the Märklin Days in Göppingen aka the Treff), and she is the English-speaker and front-person on their exhibition stand. I always buy some of their stuff! I probably have over a hundred of their accessory decoders (k83 and k84 equivalent) on my layout, and a Tams MasterControl central unit which is used for switching all my points, signals, relays, etc, controlled by the computer. So, purely as a customer, I fully recommend them, and their support is excellent.
Anyway, I'm always to happy to share my experience!
Nigel
