I've tested the SDG2042X now for two days and i am impressed. I like the touch-screen because of the fast operation of the device.
I also like that only the max. frequency of the sine-wave is limited compared to the more exensive 2000x units. That means rectangular waveforms are going up to 25MHz. Great feature for the value.
All parameters i could check are full in specification.
There is one bug with the Knop operation (the digit-position jumps one step to the right when crossing zero). That will be hopefully fixed in a coming firmware.
I did not tested user defined waveforms yet. But there are already many build in waveforms that are looking great.
I let the device running full day and did not get warm.
As usual the fan could be more silent....