I have it for about 5-6 months and it's not bad but not the best either, I consider it an average phone. I will write the positives and negatives below for you to see. (I may have spelling mistakes)

POSITIVES:

1. One of the best, or maybe even the best, battery for phones in this price range. It lasts for a day and maybe a little longer with moderate use from 100% to 0%. The charging speed is satisfactory, it charges in 2 hours from 0% to 100%.

2. Fortunately, it comes with a charger in the box, which is very good because I personally consider it "stupid" for a phone not to have a charger in the box.

3. Good photos for its price, especially the 48MP function. The Macro camera is bad (because of the 2MP).

4. The videos are okay because they don't have stabilization, but I have no other complaints about a phone in this price range.

5. The fingerprint sensor is quite fast and in a good position, I have no complaints.

NEGATIVES:

1. The screen brightness is terrible when there is sunlight and you can't see anything even with maximum brightness.

2. The speaker is very quiet and can only be heard well in silence. Also, if someone calls you, you will have to activate the speakerphone at maximum volume to at least somewhat hear the caller.

3. It takes a while to open apps (Google Chrome, games) and sometimes when I have opened a game and exit, it takes 2 seconds to close.

4. The back part, which is made of plastic, scratches easily.

That's all for now, I will add edits if I find any other negatives/positives. I believe that Samsung phones up to 250 euros are not worth it, if you want a good budget phone, get Xiaomi or Poco, they are really worth much more. I hope my evaluation helps you with your purchase :)

Reasons I bought the M12:

- Cost is less than 180€
- I wanted a newer phone (the A40 I had was over 1.5 years old and its warranty would expire in a few months)
- I wanted a capacity of 128GB and at least 4GB of RAM
- Large battery
- I consider the processor (Exynos) to be better than the MTEK, and that was mainly the reason I chose it over the A12 ... without knowing if the A12 is better or not

POSITIVES

+ Dual SIM + MicroSD for photo-video files, etc.
+ Low price (within my limits <180€)
+ 128GB capacity and 4GB RAM
+ Fast processor
+ No lag (so far I have done many parallel tasks smoothly)
+ Does not heat up at all
+ Large battery capacity of 5000mAh, which lasts at least 2 days with moderate use
+ The cameras satisfy me

NEGATIVES

- Unfortunately, it is bulkier (thickness) and heavier than I expected.
- The WiFi card is only 2.4GHz and does not have 5GHz ... something I really did not expect and is a significant disadvantage ... at least for its time.
- I struggle with the side fingerprint sensor, maybe because of the case but also because of my habit with the A40, which had it on the back.
- Absence of a super AMOLED screen ... not annoying, but if you have been accustomed to something better for years, the difference is noticeable.
- Absence of headphones ... I would call it a "sting" from Samsung. In all the models I had purchased so far, they had a good set of headphones with Samsung quality. In the M12, they are missing.
- "Poor" design of the box ... It looks like it was made hastily. For example, the back should at least indicate what it contains and its technical specifications.
- No compass and magnetic field sensors: NO

I believe Samsung made it a bit hastily, and if it were a bit thinner, with dual network cards and an AMOLED screen, it would be more competitive.

However, its low price combined with the capacity of 128GB/4GB RAM, the large battery, the good processor, and the cameras (although not something I am particularly interested in on a phone) were the purchasing criteria for me.

Well, first of all, I have to say that I am a person who comes from a redmi note 6 pro and I have to say that it is a good phone and I will say its pros and cons.
Firstly, 1: it is fast, I have no complaints about the speed.
2: it has a very good battery life and I am also impressed with how fast it charges with its 18w power adapter.
3: it has a relatively good speaker, meaning that at max volume the sound starts to distort a little bit, but overall it is good.
4: it has very nice settings that if you take the time to explore, will make your phone very beautiful.
5: as for games, it plays them in very good quality at 30-40fps, I am very satisfied.
6: it has a very good and powerful camera lens.

And now the negatives...
1: firstly, a big downside is that it comes without a case, I don't know if it's something normal that Samsung does, but when I bought the Xiaomi it came with a case.
2: the camera for me is terrible because it has many settings for the camera but the resolution is lacking in any setting I tried (I'm talking about both front and back cameras), so if you are a person who takes a lot of photos, don't get it, it's better to spend an extra $100 to get something better.
3: the software is very complicated, especially in the sound settings.

The phone is worth the money for someone who wants to be on social media, play games, watch videos, and make calls 24/7, but for someone who wants it for a professional phone (photos, videos, etc.), I would not recommend it for the above reasons