Opinions: Used BAT VK-51SE or New VK-23SE

Looking for any BAT owners out there that would have an opinion on which piece I should go with.  I can get a used VK-51SE for slightly less than a new VK-23SE.  The 51 is from ~2003 if my google searches were correct.  The 23 is obviously newer which means newer technology.  But that 51 was their top dog back in the day and all the reviews I can find rave about it.  The 51 is factory refurbished as well.

I'm leaning towards the 51, but would appreciate any thoughts BAT owners would have.