If I have to choose between the Siglent or the Rohde & Schwarz, I would never choose the Siglent.
It may have more waveforms updates per second, but 50k for the R&S is enough (for me).
The R&S can go up to 160Mpts memory depth, which is more than the Siglent has.
Beside other things: the R&S comes with R&S quality and not with the Siglent rust.
Just my 2 cents.
Edit: Typos