Your title says K track and your posting says M track. Which track type are you planning on using? It will undoubtedly make a difference as to which manufacturer's locomotives will work better on one track type or the other.

I use K track and have a mixture of Maerklin, Brawa, Fleischmann, and Roco locomotives working quite well.

M-track have a few issues or problems.

The switches may have wobbly or bent blades.

Track may be dented or not well aligned.

Don’t expect vehicles to run on Märklin track 5120. Some may, most will struggle or derail.

Avoid 360 mm counter curves and that goes for any track system. Go with the R2 switches.

Avoid switches with the old big light. Or remove that light.

Aligning and adjusting every track carefully is the key to make it work.


In my experience the type of loco or wagon will matter. Generally shorter wagons with bogies will run better than longer 2-axle or complex steam engines.

Use proper ac wheels.

Roco ac is probably the safest bet, but be aware of what coupling you are going to use. I think the new Märklin 72000 coupling works well with all modern.

Piko ac 3R will often run well. Jeco, depends on model.

The Jeco x2000 runs well on c-track but are not so keen on the 360 mm curved switches. I have a thread on svensktmjforum.se regarding some tweaks for the x2000.

NMJ usually needs a lot of tweaking, and Heljan even more and Hobby-Trade requires a total overhaul to run.

I let go of the m-track for c track many years ago and I don’t miss them.

Yes, mine does. Just be aware that short circuits from a derailure with M tyrack and newer decoders can cause them to fry. Because of the metal roadbed, there is no plastic like C track has to even buffer a short through the ground side. All the voltage goes to the decoders from both ends.

If the Roco ac model has a decoder in it from the factory it will work perfectly fine. If it has been installed by a private individual, it may depend on the decoder installed.

Most manufacturers making models for AC marklin use have designed the models with all track types in mind. However there will always be some models that are better than others.

Cheers….

Mike

Irrelevant I’m afraid

Because it’s no longer in their product range, and like any business they want us to purchase their current products!

Anyway, this is getting well off topic and not useful to the original poster so I’ll stop here.