Anyone used VOIPStunt

Anyone used www.voipstunt.com for free calls to landlines. I use skype at the mo but i have to pay (albeit cheap) for the calls to landlines. is there a catch ?

looks the same as www.voipbuster.com. you have to buy €10 then get unlimited free calls to landlines, keeping the credit for mobiles/international calls etc.. I use buster, bit slow but my connection is a bit dodge sometimes...