Hi,
I am a Hungarian student in the US and I fly with Malev frequently on the BUD-JFK route. I find them nice, the service is good and they have never lost any luggage. The only drawback I can mention is that since they operate a single airplane that flies back and forth between JFK and BUD, if it leaves late from Budapest, it will be leaving late from JFK too - this happened to my girlfriend once, but not to me. This might change now that they have joined oneworld.
I was particularly impressed by Malev once when my luggage was too heavy but the agent said it is OK since the plane was not full anyway. This is in contrast to Delta (the only other airline with JFK-BUD direct flights), who are happy to charge you $25 whenever they can.
Now only if I could figure out how to book these flights cheaper ;-)
HTH,
Tamas