I tend to do my big compound movements explosively on the concentric and controlled on the eccentric. I don't really think about the rep cadence at all, just make sure that I am getting full ROM and a controlled negative.
Isolation work is a different story though, there I do focus on tension throughout the entire movement and a peak contraction. Only exception to this I can think of would be hamstring curl variations, when I do a controlled concentric I don't feel like my hamstrings get much of a workout, the weight also has to get reduced by quite a bit. So for these I stick to the full ROM, explosive concentric and very controlled eccentric.