Update: after a couple years of use, the non-stick coating on the collar has started to flake and peel off in large pieces, even though the sides of the pan aren't actually subjected to the kinds of scratching that a pan bottom might be, because you're not cutting anything on them! It's coming off just from having things baked in it, plus normal gentle hand-washing with a soapy sponge.

I have used one of these for a long time-- I like the glass bottom, though it was never a particularly tight seal.  After living for a while with a cheapo IKEA pan in my other kitchen (I commute 1100 miles and unfortunately have two of many things), I finally decided to "spring" for a nicer pan, so to speak.  The first one arrived and was all scratched up, so I returned it and got a second one.  Filled that one up with water, and indeed, drip drip drip drip. It's from where the collar joins, since indeed, the outer side of the ring has to be looser than the inner side.  Batter won't drip through it or anything, but butter in a crust, or juice from baking fruit might.  It's not actually worse than the cheaper pan, so I decided not to return yet another one.  Overall, I'm quite disappointed, since I was hoping that by shelling out the cash for a fancier pan, I might get a relatively drip-proof one...
Update: after a couple years of use, the non-stick coating on the collar has started to flake and peel off in large pieces, even though the sides of the pan aren't actually subjected to the kinds of scratching that a pan bottom might be, because you're not cutting anything on them! It's coming off just from having things baked in it, plus normal gentle hand-washing with a soapy sponge. I have used one of these for a long time-- I like the glass bottom, though it was never a particularly tight seal. After living for a while with a cheapo IKEA pan in my other kitchen (I commute 1100 miles and unfortunately have two of many things), I finally decided to "spring" for a nicer pan, so to speak. The first one arrived and was all scratched up, so I returned it and got a second one. Filled that one up with water, and indeed, drip drip drip drip. It's from where the collar joins, since indeed, the outer side of the ring has to be looser than the inner side. Batter won't drip through it or anything, but butter in a crust, or juice from baking fruit might. It's not actually worse than the cheaper pan, so I decided not to return yet another one. Overall, I'm quite disappointed, since I was hoping that by shelling out the cash for a fancier pan, I might get a relatively drip-proof one...