To learn more about criteria rating calculation can be found on page Principles of calculation rating accounts
I was trading on this account type and I'm absolutely disappointed. Terms and conditions promise tight spreads but in fact they are widening to a huge size. Of course I've lost my deposit.
I like to use in my trading the expert advisor and with the Premium account I have this opportunity. The spread is tight and the minimum deposit is not very high.
I'm a scalper trader with my own EA and when I've opened Premium account all my expectations came true.