(Some screenshots from the video pasted below, to save having to watch it all, although it's interesting).
From the video, the MPO display looks neat, with little wasted space on text that's not needed. It is obvious what the units like pts, MSa/s etc refer to.
The supplied apps displays look as clean as imaginable, with decent axis titles with units. I can't see how those could be improved further.
The Python GUI functionality looks like it can be integrated into the normal instrument controls.
When I first heard of the Rigol, I found the idea that they'd used Android intriguing, and probably a lot can be done with it, but in terms of practicality, I'd much prefer Python integrated into the instrument. (With Rigol, I guess what could be done, is Python as a separate app installed in the instrument, communicating via SCPI? but it's not the same at all, but perhaps a compromise).
I know the MPO-2000 is not 12-bit, but 12-bit takes a super-decent FFT (by that I mean super-usable, fast responding with decoupled controls like start/stop-freq/RBW, unlike the older scopes had) to extract max use of it (since there's only so much to see on a time-domain trace view, even zoomed in), and the MPO actually does have really good spectral analysis (if they have taken their MDO-2xxxEX functionality and reused it). It's a different price-performance of course, since costs are completely different too. But I think it's still reasonable to compare some aspects such as the display/UI.
The Rigol and Siglent, although I know so little about these instruments, are for sure tremendous price-performance (who could have imagined 12-bit scopes at that price!), but that MPO is also highly tempting with the all-round features (including dual AWG and PSU) and (expectedly good) SA and Python capability, everyone is different.