i have heard this as well. Metzelers are good in the rain.

 

General rule...the longer the tire lasts, the harder the compound. The harder the compound, the more likely they will slip in rain.

The factory tires on my car lasted 73,000 miles and had enough tread left for anything short of snow and ice. Replaced them with "sport/performance" tires that are rated to last only half as long (softer rubber.)

Guess what...when it rains I don't slip and slide downnorspin the tires trying to get up the mountain any more.