I bought the Tattlers last year and tried them out. They do suck in and it's pretty easy to tell that they are really sealed. Here is my experience (I had it up on idig, so I just copied it and pasted it in here):
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I went over to Lehman's and got myself a dozen of the Tattler wide mouth lids. Today was my first time trying them and I have to say that I'm pretty impressed. I followed their instructions about loosening the bands before putting into the pressure canner and then tightened the bands when they came out. I just removed the bands and took a picture. They all sealed and the lids were very easy to use.
There is a nice little ridge on the underside of the lid. I just put the rubber gasket onto the lid and then placed the lid on the jar. Honestly, it was just as easy as using the normal lids. I'm definitely a fan and will be going back to pick up some more.
I have since bought another box because I did like them.