I have some analog locomotives (3047, 3048), c-track, and the materials for digital conversion. What I would like to know is:

1. For era 3 German trains would Märklin 60945/65 or ESU loksound m4 decoder be better (or a different one)? Both for sounds and general performance.
2. For either of these, which controller do I need (Do I have to get a central station for $500?!)?
3. Is there a guide for making scenery/what tips do you have?

Thanks.

Hi!
The answers to this question will be primarily opinion-based.
I've reached a point where I think that ESU decoders are better with respect to sound and performance. I decided not to buy any more MSD for own conversions. Other people think that MSD are good value for the money.
I don't need mfx, so either ESU V4 or V4 M4 will do for me - whatever I can get cheaper.

Märklin have about five ref. numbers that allow you to order decoders with different pre-installed sounds.
With ESU decoders you will find 100+ different ref. numbers.

Current ESU decoders have more than 500 CVs and a LokProgrammer is very useful to set them up. It also allows you to download sound projects from the web and load them onto the decoder (or have them uploaded by the dealer when you buy decoders).
With MSD you can also download sound projects from the web and upload them with a CS2 (or have them uploaded by the dealer when you buy decoders). Märklin only offer few sound projects for different prototype classes.

It seems Märklin are selling out the sound decoders. Maybe there will be a new generation soon.

Both decoders are compatible with a wide range of controllers.

Märklin CS2, ESU ECoS II, Märklin MS2, Viessmann Commander, Uhlenbrock Intellibox II, ...
You have to decide which controller best suits your needs - with respect to what you want to do, how you want to do it, and how much budget you have.