The people I know that have the P7 Plus ( two ) don't seem to have any wet traction issues of note but Tire Rack has mentioned this at least twice in their testing. I generally don't look to TR as the grand arbiters of truth in how a given tire will perform on my car given that most of their testing is done with 3 series BMWs...and that concept seems to have been proven right over time. TR is for comparison / subjective valuations and not definitively how x tire will perform on a vehicle that's 700 lbs. lighter, has a markedly different suspension, and has a 6 inch shorter wheelbase in comparison to their test mule. IMO, their testing of a certain tire can usually have a greater or lesser degree of relevance ( both within and outside tire categories ) depending on what you drive.
Besides the UTQG ratings, Tire Rack is about all we've got. Once in a while Car and Driver and Consumer Reports will test tires, but after those all we have are anecdotal consumer reviews and what your Uncle Bob had. I prefer actual tests if they exist. ... We could use good standardized dry, wet, ice, & snow tests, along with sound levels and ride comfort engineering tests: They don't fully exist.
It is hard to decide which tire is best for us. Go by the best clues.
----Manufacturer reputation is a start.
----Then actual test reports.
----You can look at a lot of collective consumer reviews.
----Also, JD Power has customer satisfaction ratings for tire brands overall.
All else is guessing.