I received my Tattler lids (widemouth mason and standard mason) two days ago. I have put them to the test and am very pleased. Here are a few things I can tell you about them:
1. The rubber rings are thicker than the rubber found on a disposable canning lid. This means the lids can imprint enough to provide as reliable a seal as the disposable lids. I had no trouble getting my jars to seal.
2. There are concentric rings around the rubber seals and the lid where the seals touch it. This is smart because it creates a few small ridges that seal independently.
3. The lids are very slightly oversized, but not enough to cause problems with any sealer rings. Because of the slight oversize dimension, it is easy to catch the lid with your fingers and open it without damaging a rubber ring.
4. Pressure canning went well. I've read that some people have trouble if they don't read the instructions. I did read them and though there are some differences between using these lids and the disposable ones, I found the process easy and reliable.
5. The wide-mouth mason lids work exceptionally well with the Foodsaver vacuum system which really surprised me. I dry-canned 30 jars with no trouble at all. I wasn't able to test the standard mason lids with the foodsaver as I lack that attachment.
I wholeheartedly recommend these lids to anyone that cans for their own consumption.