It already sounds like you made your choice, so why are you posting a question that is trying to convince us to agree with you?
Here's the OP's question: "What are other Slashdotter's experiences using tablets without a separate desktop computer?" I'm not sure how one can agree or disagree with that question.
Real Programmers don't write in PL/I. PL/I is for programmers who can't decide whether to write in COBOL or FORTRAN.