Don't worry about it. I've been running M track for 50 years and the wheels don't wear.
Mikey

Cheers guys. Most helpful.

The M-track derailment is overstated.. Any poorly laid track will cause derailment.. I have used m-track for decades and it works great on my computer controlled layout. The last derailment problem was actually caused by a HAMO loco that was converted to three rail the cheap way.. It also derailed on c-track.. I simply replaced the front bogie with the proper marklin part and, hey presto, no more derailment. Just don't do anything stupid like lay turnouts on an angle up a hill or use lots of s bends, and you will not have any serious problems.

As for rust... It is usually caused by a past owner using sandpaper to clean the tracks and removing the plating.. The tracks I bought new in 2000 never rust.. It can be more problematic if you live close to the coast - salt air.. I use a product on the rails called xxxxxxxxx (find it's name later), but the best way to keep the tracks clean is to keep running the trains - this is especially true for the center rail..

C Track until 2004 suffers from the disease. Best is to buy C Track with only the last 3 number printed, e.g. 130 instead of 24130.

This discussion comes up at least once a month!

I used to have M-track, some new and some old, on my layout. About 10-12 years ago I took advantage of having obtained some C-track in a couple of starter sets and changed over to C-track.

In terms of running qualities there is no comparison. Trains on C-track run much more quietly and smoothly. The tracks go together very positively and accurately, and gaps almost disappear, both on the base and the rails themselves, giving a much more seamless run, so that trains look much steadier than the same trains on M-track. C-track turnouts are a delight for all Marklin trains, and for all non-Marklin with the correct wheels.

As to wheel wear, I have been running trains for all of my life and have never seen significant wear on loco or wagon wheels.

The only negatives are the brittle nature of very early C-track and the poor reliability of the turnout motors (but they can be improved by by-passing the end cut-off micro-switches).

I cannot comment on K-track as I have never used it.