On Saturday, February 25, 2017 at 4:04:02 PM UTC-5, Jonathan St. Cloud wrote:
Do you crab or forward slip landing in x-winds and why? . .

I teach both (a requirement of the FAA Pilot Test Standard), but recommend and almost always use a slip (in the US, that'd be the oxymoronically labelled "side slip", not a "forward slip") in moderate crosswinds. If the xwind is too strong, I switch to as much of a slip as is comfortable to avoid wingtips dinging the runway, then crab.

These procedures are more important on paved runways than grass, because the side loads on the gear with even a slightly botched crabbed landing on pavement can cause significant damage.

As to "why", it's because the properly executed "side slip" permits a stabilized approach that continues right down into the flare (easier to teach as well), and reduces the risk of side loads on the landing gear.

Finally, when the issue of ground loops, grass vs. pavement, or off-airport landings is raised, then the answer changes to "it depends", and the pilot should be skilled in using whatever procedure fits the circumstances.