I think in early production runs that it was more of a concern (and complaint) than it is now. Also, I had same concerns last year when I purchased a
B3300 (basically same as a
B3200) and it has not been a problem. From the dealer I worked with (Barlows) I was reassured that Kubota has done a couple minor alterations to mitigate the problem, and like I said, vibrations have not been a problem with my tractor. I know some members have had complaints/issues with this in the past so maybe some of them can write of their experience.
If you have concerns, if possible, I would suggest you stop at a local dealer and start a
B3200 and then another 4 cylinder model like a
B3030 and a 3 cylinder B2X20 series for a comparison.