i only use sensi, there may well be other seed companys that are as good or even beter, there seeds do seem to be lacking from what others have said, there stock needs reinvigirating by the sounds of it, an example is there northan lights 5, its not even close to the original northan lights of the 90's. this may be true of other plants in there stock, but there jack herer is amazing.
https://sensiseeds.com/en/feminized-seeds thats a link to there feminized stock, just press the apropriate button for what your looking for. happy growing