If you are solely going for strength gains on your bench, then you need to see were your weak points are... are you getting stuck at the bottom or top??? are you tris the weak link or your pecs or maybe even your shoulders.... when you find what is hindering you then work on that part a little more than the others... if it is justa general lack of strength I would start to lift like P'liftiners, not train to failure and work on explosive speed...