against some of the regs at 10nl i do it and i think it needs to be done vs these players because they can think ranges and tendencies to a certain degree. against a lot of players, especially at 5nl and lower, i think it's not necessary. i think the main point at micros is the learn to exploit your opponents (ie by learning to value bet and bet/fold vs passive/call-happy ranges) than to be overly concerned with preventing them exploiting you (at 10nl and below) because most aren't doing it.