These scopes are competitors to each other, and presented here are a few home truths on how they stack up. CORRECTIONS & CLARIFICATIONS BELOW...
o You can set a user default on the Siglent by writing your current settings "To Default Key" in Save/Recall Type To Default Key. Apparently it's recommended to do a factory default & secure erase first.
o For the Siglent, to set the expansion point around the trigger, Utility Reference Pos Horizontal Ref: Position Horizontal Pos: 10.0%
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Update 3 July 2021: I've had the Rigol MSO5000 on the bench for a couple of weeks recently working on a mixed signal MCU based device. Firmware is 00.0103.00.01, the latest available at the time. Some random additional comments specifically on the Rigol...
Bugs:
o One of the PVP2350 probes failed: the scope & probes were stored in Rigol's carry bag, with a front panel protector. It's not been taken outside the lab, & I'm the only one with access. At first it seemed to be just intermittent, but finally it failed completely. It looks as though the probe's 9Mohm resistor failed as you can still see fast transients. As far as I can tell there isn't a nondestructive way to disassemble, so I had to purchase a new one.
o As mentioned in the video, there is a limitation in that the search function only works on analogue channels.
o The 1ns edge trigger delay on LA channels really needs be fixed, but at least the LA's 1GSa/s: the Siglent's 500MSa/s on digital channels becomes marginal in today's high speed MCUs.
o The following timing measurements aren't available on the digital channels: +/ pulses and +/ edges.
o When using the SPI trigger, it permanently leaves a bit match template on the screen until the scope setup is reset or reloaded.
o I had a complete freeze on one occasion, needed a power cycle, when adjusting the horizontal position.
o The sticky labels on the individual LA probes seem to be slowly coming off.
UI & usability:
o The menu continually getting in the way is really, really annoying! Tektronix MDO3000/4000 optionally offer transparent menus and on screen overlays like measurements which is a reasonable compromise. Alternatively, the Siglent dynamically resizes the waveform display to accommodate menus. The Keysights have a completely static display layout, with a dedicated area at the right hand side for measurements etc: while this permanently reduces waveform display real estate, counterintuitively I still much prefer this approach.
o Having the vast majority of things available on the front panel rather than on the touch screen is greatly appreciated. The front panel is really well laid out IMHO, not too cluttered: Keysight and Tektronix take note! Number entry on the touch screen works well.
o The ~1s delay I complained about in the video when changing the timebase is less irksome than I felt before, I think you get use to it.
Feature limitations:
o AWGs would be more useful if they had +/5Vpp rather than just +/2.5Vpp maximum. As they stand, they're marginal for generating digital test signals for 3.3v logic, and useless for 5v logic.
o There isn't a way to copy an SPI decode setup to the trigger (you can copy an SPI trigger setup to the decode).