VTEC engagement should be smooth, it's a transition MORE THAN a change over.
Granted, my old B16A CRX "felt" like nitrous when VTEC engaged, but it smoothly transitioned into it and pulled massively harder, noticably. The motor was all stock, just a swap.
People want VTEC to rip into action like that's how it works. Those parts that make that happened are govenerned by electricity and smooth metal pieces gliding through tight tolerances with lube. If it KICKS into play, something's up (or your head's built like that). But normally, VTEC's actuation should be smooth, but powerful.