There is a new 8051 C compiler in beta test that beats Keil's compiler by 35% code size, and 14% speed, on the Dhrystone benchmark. And, there is no need to select a memory model or use special keywords to control data placement.
More details here: www.htsoft.com/.../silabs8051beta
I have to agree with Jack, although I think that making mistakes has little to do with what he considers "competence". When I have trouble with macros I usually look at the preprocessor output, I don't bother to debug them in assembly.