I take the feedback system seriously and compose my feedback wording carefully. In some cases, the 80-character limit is not enough to leave a meaningful description of the transaction.
This is not just for negative feedbacks. In cases where a seller/buyer was particularly nice to deal with and went out of his way to satisfy the other party, he deserves to be rewarded with a feedback that includes at least a brief description of his efforts.
By the same token, a particularly nasty member should be exposed with some details. There are cases where a member exhibits more than one type of offensive behaviour that cannot be described in 80 characters.
I believe the limit should be at least 150 characters.
