I rented the 16-50mm f2.8 PLM and it arrived yesterday. They included one B+W nano costed clear filter as part of the deal, so I just bought a single Platinum (Best Buy store brand) multi-coated UV filter as backup. When playing around with them last night, both seemed to do ok with image quality, but both introduced a noticeable lens flare when a light source was just out of frame unless I was zoomed in about 28mm or more. So all in all they are about equal. During the day shouldn't be much of an issue, but would be a big one when the track lights come on at night. I'll be track side instead of in the line of fire, so they'll come off at that point. I did talk to the track a bit, and they may not allow the shot I was hoping for anyway, but we'll see. The race team is willing to give me a crew shirt to sneak on. Lol Now to hope the rain holds off for us.
And yes, I got the insurance on the lens.