Now I'm finding out that it is not just cheap, but bad cheap.
For a few dollars more... I haven't bought a scope yet, been fixing notebooks and cell phones without scope since 2014ish. I need one. It's one the long over due things. I've been watching videos recently, in fact no sleep until well past 3 am this last few days. And DSO2C10 is one of the considerations. A few points that I learned from watching youtube videos.
A) Most of the bugs are due to chips getting hot, so installing heat sinks onto those chips solves most of the problems. Size is 28 by 28 mm and height is 20 mm and you stick them on glue, not the self adhesive pad because one of the chips is lazer etched and has a dip in the middle. Also you change caps on the power supply and install some heat sinks there as well. Plus you wash the flux from mother and button boards. Here is a good video with the mods --
(just look what is being done and repeat, monkey see monkey do)
So taking care of some flux, installing anti static diods into USB port circuitry (there is unpopulated space for them), installing better caps into power supply, installing heat sinks two on main board and several in power supply takes care of freezing and some other bugs. But...
B) ...and this is the big one, its sensitivity seems to be around 170 mV. Bellow that threashold it does not see signal. So around 0.2 volts. Now I don't know much about scopes but that seems sort of low. I can see situations where having this scope won't give you extra set of eyes into things. So this is kind of the decisive factor for me.
C) Model DS02C10 and DS02C15 are the same. DS02C10 can also see 150 MHz, no mods are needed. In fact model DS02C10 is same as DS02D15, it has everything related to signal generator on its board, the later editions do. If you buy DS02C10 now, chances are good that it will come with signal generator stuff installed on board. All you need is firmware and calibration. But here is the thing, it's just a few dollars more, so you might as well get it the top notch model. On ali it's showing 16000 rubles vs 19500, that's 200 vs 250 bucks difference between bottom and top models. Of course on some kind of sale these prices will go down. So let's say bottom model cost 150 and top 200.. Anyway you spin it this is a 200 dollar oscilloscope.
For a few dollars more there are much better oscilloscopes, especially those that are more sensitive. Namely SDS1102 is just the same price, around 200 bucks. There is also SDS1104, and then there are rigols for around 350 bucks.
I think it's better to spend a little more money for a thing that will last you next 10, perhaps even 20 years.
300 to 400 bucks seems to be the sweet spot for the cheap one. But that's not expensive. Because I bet you have an iPhone for 800-ish and air pods for around 200 ish which you replace every 4 years or so. All things are relative and this thing is a new set of eyes and ear and nose, a new sensual organ that allows you to make money in a new more efficient way.