To my best knowledge the drains as they are now are designed like they should be; they should be devastating to the person we target.
The fundamental problem with the drain mechanics that most PVP encounters are very small scale; if we find only 1, 2, even 3 people travelling in rather loose groups, we can have a field day. In towers PVP, drains don't do *that* much since, again, we can only affect one target and by the time we land Divest the target is probably already at 10% HP.
In medium-scale 4v4 or whatnot, we can do "as intended" by draining support toons so that our side can kill the other guys more easily, etc. But if it's 2v1, 2v2, what have you, a Trader is going to flip the world upside down, and that's what we're designed to do.
We were built to be awesome in 1v1 combat, and that's how it should be. If you plan on going somewhere alone with a Trader on the other side then you are going to be having some difficulty, no questions.