Caterpillar 3126b engines

I have always respected Caterpillar an Cummins Diesel engines but since we lost a rv totally to fire we are looking for a replacement .Some are powered by the above mentioned Cat engine an reading different Fotums an various other places i get feeling this is not a good engine an some will even say avoid it.Anyone have personal experiences? I am talking about 1998-----2003 year production engines.