Don't compare it with a Keysight 3000 series. The UI of the Keysight 3000 series is quick and free of any lag. And even with 4 channels switched on plus some digital channels plus enabled decoder it will never show any lag on the screen.
This RTB2004 needs to be compared with a Rigol 2000/4000 or Keysight 2000 series, but not the 3000 series.
On the first glance I thought wow, but after watching some reviews I can say: "what I have seen of the R&S scope does not impress me too much".
· The UI is slow and often lags.
· Almost any reviewer showed that they needed several trys until they could move a waveform on the screen (if more than one was shown).
· It also was often visible that a press on a button (touch = on the screen) often did not work and needed a 2nd or 3rd try.
· The screen is glossy. In my case such a scope is always located above my eyes - I would see reflections all the time.
· Immediately the screen is full of smear and fingerprints
I am sure this is not a bad scope. It shows some nice ideas and I am glad it is there, as: the more competitors, the better the products and the lower the price after some time.
Now, if somebody finds out how to hack the economy 70 Mhz version (still 1900 Euro + VAT) to a fully optioned 300 Mhz version, then this will be a nice deal for many people (though still not for the Rigol DS1074Z buyers who are on a 500 Euro budget).