I am surprised that you are taking such a hard line on this.
Haha does it really come across like that? Oops...
What I'm trying to say is there are certainly legitimate reasons both to drop and continue this unit. Obviously I can only offer my perspective, but having an extra semester, or having to pay more than absolutely necessary at uni would be a major hassle.
As I mentioned in my first reply, if continuing the unit is going to make OP miserable and become detrimental to his happiness, then of course he should drop it. Personally, for the reasons I've provided, I'd be hesitant in doing so.
Steve-o, it's absolutely up to you to make what you believe is the best decision - and don't let me or anyone else tell you otherwise. But, in making this decision, make sure you're considering all the factors
