Originally Posted by: Goofy 
You shall only answer YES or NO.
Do you want an complete digital system without to upgrade and bugs?
I cannot simply answer that question with YES or NO.
I want a digital system that reliably does what I need in a user-friendly way without disturbing bugs.
So probably I should say YES.
I am not against upgrades. I appreciate the new functions that my Central Station 60212 received with ESU upgrades. With the latest "Märklin" version 2.0.4 it was missing a lot - missing too much.
My MS2 got several upgrades, but the old bugs remain. This is disappointing.
OTOH I appreciate that an upgrade extended it from 10+1 locos to 40 locos. Upgrades are not bad.
When I bought the MS2, it didn't even support Master and Slave correctly. Locos with mfx could only be used with the Master, the Slave could only use non-mfx locos. They should have been ashamed to sell such an imperfect, incomplete, limited system. They added Master/Slave mode with an early upgrade.
The CU 6021 is very good in all aspects mentioned above - limitations are supported protocols and address range. Perfect, but capabilities are somewhat outdated. Very efficient user interface and a very well working speed knob.
Intellibox is also very good. Mine has version 1.55 as I didn't bother (yet) to buy version 2.0. Speed knobs are a bit unreliable, so hardware is not the best (I've heard from others who replaced the speed knob encoders, so I'm not the only one).
MS2 is not user-friendly IMHO and has a nasty bug when using DCC and MM at the same time. An upgrade to fix this bug is long overdue. It is not user-friendly because it is small and has only few keys and a small display. But because it is light weight it is a very good controller to be taken to club meetings. It does what we need at club meetings.
The CS2 is not user-friendly IMHO. The user interface is not efficient for me as I need many "clicks" to do things I do frequently. I think it is complicated and often counter-intuitive.
Many different controllers, many different needs. Good to have a choice.
MRR controllers, TV sets and trains in 1:1 are all the same nowadays: they all have a built-in computer and many need software updates to work as expected.
Software development always takes much longer than expected and you always have bugs that slip through quality assurance - or even known bugs that are difficult to trace so they ship the software with known bugs ...
Do not buy early if you don't like upgrades, buy a mature system.