Gimpel, you should be more active in this conversation, since you started the thread. Being an active participant builds relationship with the people that you are trying to convince; it also shows that you are genuine about what you are asking. Otherwise, it just looks like a planted advertisement for Belarus.
A friend of mine had a 420A, and I spent a good bit of time scouring over it. He bought it real cheap, and it ran ok, but it was a risk to own. After looking over the designs of the tractor, I would have passed. Belarus may have come a long way, but that has to be proven, not trusted at the word of a new poster on MTF. And, personally, I bristle when a tractor with a questionable past is lauded over what is being offered by other foreign manufacturers, without any current history or proof of reliability.