Don't miss the Siglent UI apologetic thread above
Between the two of you I can't decide which way to go, but at least it's entertaining.
I'm just saying that I wouldn't trade a better response in the vertical controls for the row of buttons down the left side of my Rigol. I know which is more useful and which will waste more of my time.
Question: If YOU were running 3 or 4 channels at 100Mhz or better, would you really be satisfied with 250M per channel? I know I'm generally not doing that, but this is a theoretical question.
It depends on what you're looking at. If you're actually looking at four signals with 100MHz base frequencies then, no it's not enough.
Then again, a 100Mhz oscilloscope
isn't suitable for doing that - you'll see four 100Mhz sine waves on screen but nothing much in the way of harmonics. In that scenario you should be looking at 300MHz+ oscilloscopes, maybe 500Mhz for real signal fidelity.
Back in real life: I know I'm only going to look at signals in the tens of MHz range on my DS1054Z, maybe 50MHz tops. In that scenario 250M per channel is enough for me (it's 5 times the Nyquist limit, plenty for signal reconstruction).
If we apply the same criteria to the Siglent then I don't believe the extra sample rate will make much real difference.
5x Nyquist vs. 10x Nyquist? Not much difference, maybe a pixel here and there.
(nb. I'm willing to look at some screenshots if anybody can demonstrate otherwise...)
OTOH: If you're going to hack the Siglent to 200MHz and look at four simultaneous signals with 100MHz base frequencies
then it will come into play (though maybe not as much as you might think - Nyquist theory works, bitches!)