Dave,

I've been using a small PZL now for 3 years with no leaks.

It's actually my second one - the first also didn't leak, but the
window got all blurry (UV, moisture, bugs, plants in the liquid?) so I
had to replace it. But it didn't leak either.

I do mount mine a bit differently, against the face of the panel,
without using the supplied mount. Don't know if that makes any
difference.

And it actually came in handy once when the visibility was so bad here
in S IL that I had to fly a compass heading to make it home. Nice to
have to crosscheck the magic boxes.

Kirk