Hi Nikos,
for almost two years I have been using a Quato IntelliProof 21. I am very happy with this display and especially their customer support. Quato IntelliProofs sport hardware calibration, which is a real plus in my eyes. In some European countries, Quato offers a 5 year warranty including free transportation.
Back when I bought the monitor, I compared the various top brands in regards to their abilities for my B&W and color work. The Quato was the best offer for me at the time (price and performancewise).
The newer line of Quato IP 230 seem to have even better panels and improved hardware under the hood.
I don't think you can go wrong with them. Nevertheless you should compare them to monitors like EIZO. The older Radon series was much cheaper and has nothing in common with the current Intelliproof lineup.
Cheers,
Andrew