Why would you expect it to be better in Run mode - after all Stop mode should be the easier one?
I had expected Run mode to be unaffected since, in my understanding, it only acquires a screenful of data anyway -- hence I thought the "deep memory" access with its wait time would not apply.
Like most other DSOs, the SDS2000X stops acquisition while the users move the trace around on the screen. It resumes after a short timeout and only then the gap can be filled. By contrast, in Stop mode acquisition is not running anyway, all the data is already there, hence also no delay (except for the data exceeding 10 Mpts in the SDS2000X Plus).
Thank you very much for the details in any case! It's not a severe limitation, but still a bit disappointing to bump into things my measly DS1054Z does better... It may be an indication of Siglent's focus on powerful analysis, where interactive viewing and manipulation occasionally take the back seat? Like with the lack of a horizontal vernier, which also was a bit surprising to me.
We often see such complaints.
Users that come from some old analog CRT-oscilloscope - or older digital scopes - are disappointed that with their shiny new DSO they can't just enable X-Y mode without bothering with the timebase (which is just disabled on an analog scope in X-Y mode).
And why can't they have their beloved alternate trigger (to watch two unrelated traces at the same time) and why the heck isn't there an ETS-mode available, as even the old Rigol DS1052E had?
We cannot even be surprised, because one needs to know a bit about the internals of oscilloscopes to understand the reasons why progress does not always mean just additional features but can also lead to different solutions. Sometimes it looks like a step back, but almost always a rationale can be found for it.
The most important aspect for any UI is a timely reaction on user actions. You get this on the SDS2000X Plus: as soon as you try to move the trace, no matter what direction, and no matter whether you use a touch gesture or the position knob for this, the trace will follow almost instantly. It's just the gap that needs a little time to be filled under certain circumstances.
Folks have complained that the DS1000Z cannot even move the traces vertically without delayed jumps, so it's hard to believe that it can do it smoothly in the horizontal direction. Maybe it does when you use a fixed memory length, so that no new acquisition is required. But in a setting like this, an SDS2000X HD renders smooth and gapless (and without any jumps) of course.