OK, quick background: looking at new skis - have two shops that carry the model I'd like. One shop sells it flat, the other with the "system" binding. The shop that only sells the ski flat does so for two reasons. First, they say that the ramp angle (sometimes have seen this called the binding delta) of the system binding is too steep, and second, the system binding does not allow for any adjustment to the delta angle. They contend that, through their years of biostance analysis of their customers and other skiers, an overly steep ramp angle (more than 4 degrees), like those found in most 'system' bindings, is actually a hindrance to good skiing technique and outweighs any flex advantage a 'system' binding has. For example, they say that the steeper ramp angle doesn't put you over the tips, but actually forces you into the back seat.
I realize that this is highly subjective in that everyone's body shape, ability level and even to a certain extent how one was taught to ski will have an impact on what feels natural in terms of your stance, comfort and how one likes to drive one's current set of skis (thinking that some skis may require a very different stance than another set). Still is it that subjective? Are there any general rules that say you want a little bit of forward lean, but not too much or you really should be completely neutral (if that's even possible)? I've seen a lot of discussion on various threads here about ramp angles and such, but there doesn't seem to be much about what's supposed to happen if you change your binding from a three degree ramp to a flat platform or if you double it to 6 degrees. All other variables set aside, how would that change the performance of the ski?