Johnnantias. RB250 & Rb300 cannot track Koetsus. I have tried and it sounds like sh*t. I guess it may have sound nice to some, but I am sad to say those individuals would be better off with something from Best Buy. Having run the same cart (Koetsu Rosewood) on arms like an Ittok, Morch, Sheu and SME it is clear that an RB is not suited for quality carts.
I previously said an RB is a good budget arm, but in reality even that is not true. Having compared a modified RB250 against arms that are availably for very cheap like an SME3009 and Mayware Formula 4 the RB is only a good buy for a person with no setup skills.
Lastly, I am not a snob. I spend many hours listening to and a large chunk of my disposable income on music. I could not care less what brand of equipment I use; in fact all my amplification devices (phono, pre, power) are home built. Like most audiophiles I simply want the best possible music reproduction for my money. An RB250/300 fails miserably at that.
Regards
Paul