Considering that the max output of MS is 3amps (48VA) you should get the 60055. The 6001 gives < 3amp output with no reserve, so you are underutilizing the MS2 considering that the MS uses some current. Output of the 60055 is 5amps (60VA).
Blue case Xformers have even less output than 6001, I believe.

mrmarklin & HO -- Thanks. Your recommendations for the #60055 confirm what my newbie head expected. It appears that a #6001 won’t give significant capacity improvement over my old blue-case #6153 Xformer. FWIW, measured voltage from its sockets are: Red = 0-16V; Yellow = 16V; Pulse = 26V. I believe its max output is 2 amps. (I have two others that are 1-2V higher across each socket. I don’t use them.)

The highest load I’ve placed on my simple 8-foot test track oval with the old transformer has been three FX locos pulling a total of ten lighted coaches (20 bulbs). Surprisingly, I’ve not noticed degraded performance, nor experienced a transformer overload shut-down. Still leery, but may be temporarily OK. I’ll start shopping for a more future-proof 60055.

Related = I’m very obviously still just learning, and have not figured out how to check track voltage and current through the MS2 (bought new a month ago). From its “Information” Menu, it displays: SW version 1.3; HW version 2.0; LDB V 009 (10/2). Is this up-to-date software? Finally, I don’t know what “LDB” means. Thanks again -- DG

With respect to running a loco, it depends on a) the voltage of the transformer and b) the speed setting on the transformer.
If you run the loco full speed with 19 V from a blue transformer (instead of 17 V from a grey transformer), then it'll be faster, but motor, light bulbs, and maybe even decoder won't last as long as with 17 V. No difference if you keep voltage below 16 V.
If you reverse direction the decoder could die within seconds (some blue transformers have reversing voltages of 30+ V while the grey ones should have 25 V).

The voltages vary very much, so you must measure your transformer - you cannot rely on the measurements of someone else with a transformer with the same ref. number.
Grey transformers are 6646 and 6647 - the only types allowed by Märklin for analogue operation of modern digital locos.

I’m very obviously still just learning, and have not figured out how to check track voltage and current through the MS2 (bought new a month ago). From its “Information” Menu, it displays: SW version 1.3; HW version 2.0; LDB V 009 (10/2). Is this up-to-date software? Finally, I don’t know what “LDB” means. Thanks again -- DG

I just received a 60653 MS2, plus 60113 interface and I am in the process of testing its capabilities. I have a 60055 transformer on order, but it has not yet arrived. As such, I have been using a 66185 (120v 18VA 20volts) transformer from a starter set to temporarily power my test layout. The output voltage of the 66185 is approximately 20.4 volts, as measured by the MS2. The transformer is powering two locos, and 3 digitally controlled turnouts. Should I be concerned about the higher (than the 60055) output voltage from the 66185 for a few weeks until my 60055 arrives, or is the voltage in an acceptable range? Thanks...

Tom...Thanks for the quick answer! In looking at the specifications on one of the dealer sites for the 60055, it stated that the output was 16vac...so I made an assumption that I was "over volting" the layout with my 66185....Dan

Tom..Thanks for the detailed description of what goes on inside the connection box. As a newbie to Marklin, it is quite interesting to me how things work in the Marklin world. Your information led me back to looking at the 66185 starter set transformer, and I discovered that the output specified is 20.8 volts DC, not AC. I did not disassemble the track connection C track section that came with the starter set, but it looks like it was probably not designed to work like the 60113 track connection box (no rectifier.?.). Dan

Yes (and nothing else: the 24088 and 60115 only contain a bridge rectifier and a capacitor).