I think the ONLY commands that "leverage the capabilities of the chips to the max ..." are those which configure / enable the core-independent peripherals (PWM, timers, etc.) Otherwise, you're running through the interpreter.
That being said, speaking for myself .... 80 - 90% of the projects I've built only really need to be faster than ME, not as fast a lightening ... so PICAXE works. But, I've also had projects where I want things to be much faster ... and I've enjoyed embedded PIC development for that ... I mean ... if you haven't played with Direct Memory Access ... you're missing out!