The Graduate Research Paradox

I'm starting to think about spring semester, and I've hit a bit of a conundrum. 
You see, this summer was mostly squandered away waiting either for cultures to arrive or to get equipment to work with anaerobes.  By the time everything was good to go, it was August.  And classes have plagued my productivity ever since.

I would LOVE to tell classes off next semester and just get down to the brass tacks of my research. 
I may be able to.  You see, my first semester I took 10 credits (3 classes) while working as a research assistant for my lab*.  I was paid by a grant completely unrelated to my thesis, so I was paid as a tech instead of having to TA.  I didn't know (and no one the graduate office bothered to tell me) that I really only had to take 4-6 credits at the 600-level.  In the end, it kinda works out, as of now, I only have to take 1 more class, and 2 more seminars.

My reasoning for putting off taking that 1 class in the spring are: A) The class offered doesn't really apply to my area of specialization and B) I have my qualifying exams + thesis proposal defense in May.  I would rather prepare for my exams, as well as get some serious research done for my preliminary data/ have a solid proposal defense. 

I think my advisor will go for it. 
A better class becomes available in Spring 2012 (I missed it last spring), so there's always that.  I wonder how many other graduate students do this?  I know that the exams are going to be tough.  One of my classmates has a mutual committee member, and she said that his exam was insanely difficult.  This particular member has already told me that he'll be testing me on possible genetic manipulation that I might use in my research.  Genetics is not my strong point.  In theory I'm ok, but I've had very little practice with it.  All the more reason for me to really prepare. 

And now...instead of working on some new ideas, I have to wade through another assignment due on Friday.  It isn't that I don't enjoy my classes; I just wish they would quit taking up so much time.

*I should clarify that my particular PhD program doesn't have rotations.  You basically have to be approved and brought on to a lab prior to starting.  If the lab takes you on, but doesn't have funding, you can always TA your way through (though I haven't heard of this happening).