It matters ALOT. Our standard poker BR model is built on Kelly Criterion (google it) which recommends number of BIs given winrate and standard deviation. Kelly mathematically proved that you MAXIMIZE YOUR $$$ WON if you move up at predetermined number of BIs (in our case usually 20 or 25 BIs) i.e. move down when aforementioned BR gets cut in half. Deviating from this model lowers yor profit - as simple as that. And taking 2BI (extremely thin) shots and having to drop 3 times means 6BIs are wasted and yes, this will seriously affect you in the long run. I don't know how to explain this better.