i've had a qck, then a puretrak talent and now a zowie g tf-x.
The zowie is the newest one by far, there have been no changes for the qck and puretrak (not that i know of to be fair). The Zowie feels like a mix between hard pad and soft cloth, while being gentle on your mousefeet and still fast. It has stitched edges (hooray) and a very grippy base. It feels a tad slower than a fresh puretrak talent, but much more consistent and it feels like it will hold this consistency for a while. In the summer i had problems with the puretrak and sweat (light sweat but still sweat) where it would have loads of friction in some places but little in others.
That's why im staying away from old cloth pads atm, the tf-x doesnt soak up anything and feels great and very well made (no edges fraying out, or any errors in production).
It obviously comes with the price, qck+-heavy is like 20-25€, puretrak talent costs me 25€ and the zowie g-tf x (which is bigger than both by a bit) cost me 35€. i hope it will be worth it, had it for three months now. I guess it will last me much longer than my puretrak (~6 months till it became uncomfy, 1 year till barely unusable).