"Do NOT directly compare the PIC18-series reported compiled BYTES with the non-18 series compiled WORDS. They are NOT the same thing. You are not comparing like with like."

Thanks Melanie for putting lights on it. So as i can understand it will take about the same memory space at the end considering WORD compile/Bytes. Am i right on that?

Can we assume that 18F2525 will run faster than a 16F648 for some task?