Hi, hope my reply will help you guys. The ADC of the DSO2512G is MXT2088, which has built-in dual ADCs, can run up to 125Mhz, and can reach a single channel of 250Mhz at 180° clock phase shift, so the physical sampling rate of DSO2512G is 250Mhz. But why declare 500Mhz? FPGAs can actually achieve "equivalent sample rates," and competitors claim their toys as 500M and 1Ghz sample rates, so you have to make a compromise between market survival and integrity. The 8091 chip can easily drive a 50R load, and the bandwidth exceeds 200Mhz at G=1, so the analog front end will not make any restrictions on the 120M frequency. No CMOS op amp has a high "slew rate," so measuring high-frequency signals requires an X10 probe to reduce the input voltage. All of Fnirsi's oscilloscopes over $50 use the MXT2088, and the actual vertical sensitivity = 100mV due to the lack of a 10x gain amplifier (claiming 50mV is because they use software to process waveform amplitude).
In my opinion, the DSO2512G is the best oscilloscope with the highest bandwidth/10mV sensitivity/performance for less than $90, if you find a better model than the DSO2512G at this price, please let me know.