I charged them one by one with terminals to make them more balanced since they are in series. In a discharge test with an artificial load of 200 mA, they performed just fine. Very good purchase and fast delivery.

Batteries are fine. Cheap, connected and so far performing well. I have put them in a body shaver and they seem to hold up. Time will tell of course for their durability.

Even after several charges, the Philips shaver fails to reach more than 70% of the speed of the mains connection with its batteries.

I put them in a hair clipper that no longer worked and now it works like new.
For their installation I needed a soldering iron and a slight modification of the original wiring, so depending on the device they will be placed in, you should have the appropriate equipment and experience.

Update: 3 years later they perform like the first day!

I did not have the chance to use them, as they did not suit my needs for which I purchased them, so I returned them. I consider it a good product based on the reviews I read, not based on my own experience.

In whatever device I replaced its built-in batteries with these (from an electric vacuum cleaner to a wireless VHF), its performance improved significantly.

After 4-5 charges, they work as they should.
I have put them in a hair clipper that I mainly use for beards... in my opinion, their purchase is worth it.

I changed the batteries in a rechargeable shaver with these.. I am satisfied, it shaves stronger and faster although I would prefer more mAh, but I couldn't find them here on Skroutz.. Now, only time will tell.

I put them on a wireless phone. Their price is very good (note that in the market for wireless phones they are circulating with 550mAh). They are also branded (Powertech is a company that, although not a "big" name, still produces low-cost reliable materials).
I will monitor it and keep you informed.