In my modest opinion, he will say that Rigol is quite good for its price, but if I stick to the parameters, in Spain:
The Rigol DS1054Z costs € 400 with taxes included.
The Siglent SDS1104x-e costs € 510 with taxes included.
The price difference is € 100, it is 25% and not 50% with they say out there.
If we have to hack the two oscilloscopes, we get:
Rigol 4 channels, 100Mhz and serial decoders, for € 400.
Siglent 4 channels, 200Mhz, serial decoders, Wifi, AWG license (option to expand to AWG) and MSO license (option to expand to MSO), for € 510.
And if we enter into technical characteristics:
Siglent is better than Rigol in:
Siglent has 2 Adc of 1Gs, being able to work the 4 channels at 500Ms
Rigol has 1 Adc of 1Gs, being able to work the 4 channels at 250Ms
Siglent Wfm = 100,000, up to 400,000 in segmented memory.
Rigol Wfm = 30,000.
Siglent has 14Mb x 2, that is 14Mbs per 2 channels = 28Mbs.
Rigol has 24Mb.
Siglent has FFT of 1Mp, really usable and reliable.
Rigol has a toy FFT.
Siglent has SFRA or Bode Plot with an AWG (any AWG from Siglent works).
Siglent has Wifi, remote control by web, option to expand to AWG and MSO.
Siglent moves faster in the menus because of its more modern hardware.
Siglent has functions of tables and markers in FFT and serial decoding, etc. They really help a lot.
With this I do not say that Rigol is a bad option, much less, but if seeing its technical characteristics the Siglent is one step above the Rigol, and the price is also a step above.
It all depends on whether you want or can spend those extra € 100.