Sure shaman I understand the principle behind flushing but there are a lot of variables: eg. the water retention capabilities of your soil, the amount of nutrients in your soil when it's fresh... etc.
If you flush then your soil will be wetter than it's ever been since day 1. This is a radical change in the environment that the roots are living in. In some cases this might be good, in other cases might be bad. And my suspicion is that, depending on the age of the soil, if you have been watering sparingly for weeks and then you flush, AFTER all the flushing water has run off, your roots are in an environment which is very different to before the flush. Some soils contain nutrients which are slow-release, meaning that the water remaining in the soil after the flush might cause nutrients to be released over the next, say, 72 hours.
Sure most of the nutrients will be washed away but exactly what happens with the soil in the next few days after flushing...? I wish I could back up my comments with some scientific proof or personal experience but I can't.
I think I will try a flush for the first time with my current grow - it's such a hot topic of debate!