I haven't seen RR 2003, but did use RR 2006 and loved it - can't imagine the price difference to be more than $10-15 at the most.......I would go for the 2006 one
Been using RR-biochem for the last month or so it seems that goljan has thrown it down again. Keeps everything very clinical...HY..lots of associations. You gotta love those associations...they just stick in the cortex somewhere.