New 'Vinyl Flat' flattener?

Got my VinylFlat/Groovy Pouch combo today! Did my initial test on a copy of Eagles The Long Run that would launch the stylus out of the groove on the outer cut. Followed the instructions and four hours later the album is about as flat as I could ask for - only minor vertical movement of the cartridge and tonearm on each revolution.

So, this is a product that garners my full support and recommendations!

Picked mine up last night, free next business day delivery from Texas to NY. Well packed (but no fancy retail packaging which would just add to the cost) , and much heavier than I expected. I havent had a chance to test it yet. Somewhere around I have an album bought new a couple of years ago, that was so warped and rippled, it was completely unplayable. I'm gonna round that one up and put it to the test in the next few days and will report back. Certainly on first blush it appears a well-made device for the $$$, and they shipped immediate.

I tried mine out today with the pouch. 5 hours heating time and a couple of cooling hours. Pretty severe edge warp gone in a new pressing of Lucinda Williams "West" which all four copies I tried were next to unplayable. So far, so good.

After flattening, is there any negative effect on the sonics of the album? In other words, is there detectable groove damage?

No negative effects that I can hear. The Band's Rock of Ages (2nd LP) is in the flattener now. I'll try and post some short video of before and after.