The sparring can be as light or as heavy as you want to make it... Karate won't reprogram your instincts and give you something to fall back on when the shit hits the fan though... or get you in even half the shape boxing will.

Ask your parents, why Karate? What is the point in it?... once upon a time when it was taught properly maybe... but now days some soft desk jockey is training it in some church hall (unless it's my mate's dad teaching Tai Kwando... but that's a different story... )... it's not gonna give you any benefit... some drunk bastard will wade into you with wind mills and you'll be left on the floor... thinking... what the fuck... why wasn't I read for that?