In light - medium air I always fly the jib across in tacks but in heavy air I always seem to stall if I try that. Backwinding the jib is the easy way to tack in heavy air, but the guys above are right; you gotta be careful not to do the backwards-capsize (done it too many times. hehehe)

I find gybing in heavy air not too scary because when you're going downwind the relative wind is obviously much less; I mean if you're getting 10 knots upwind in a 30 knot blow then you've got 40 knots of wind in your face (more or less; actually (30 sin 45*)knots of wind) but downwind you're subtracting, so it might only be 10-12 knots. Anyway. I'm sure in a REAL blow it'd be rough, but I haven't sailed in much over 35 knots. The one time my buddy and I knew 50-knot winds were on their way we headed in. Better safe than sorry.