I can't speak to the relative quality of the tools themselves HOWEVER the myriad results of long lasting repairs performed with the Time-Sert tools would have me looking no where else. Time after time we can read here how Time-Sert has saved the day; equally read are those posts where cheaper stuff was used only to fail shortly after being installed.
If the cost for what might be a one-time use tool is an issue call around your local for-hire shops and get price quotes for the repair. I've heard average price per hole is about $400, some as low as $285 or so.
ATD is basically a Timesert chinese copy. I've used the timesert to fix numerous helicoil blow outs. I've not used the CalVan, most all the other Calvan stuff I have used has been good quality so I have no opinion there. Timesert HANDS DOWN over ATD. I did research the Calvan before I bought the Timesert. At the time I had to have something fast and Timesert was the quickest route.