Tracy,
My tractor is an "old" JD 855 (24 hp), 1997 model. The x55 series survived as THE line of hydrostat JD CUTs for nearly a decade (maybe more). Since the demise of the x55s, there have been two (?) evolutions of JD CUTs. The backhoes also evolved. The 47 and 48 hoes are the evolution, more or less, of the JD 7 and 8 backhoes.
I found a #8A backhoe 3 years ago or so, and am really glad to have it. I am sure the 47 is a great hoe, but...you will find projects where the extra power of the 48 will help get the job done.....You will also find jobs too big for the 48 to handle. However, the extra power of the 48 will maximize the usefulness of your tractor. Who knows what tomorrow's backhoe task will be?
OkieG