Hey, this subject is right down my alley. I TA biochem 154 and worked with Steve (Dr. Kim) for a while. I actually liked 153L and didn't think it was that hard. One reason that I think it is really good is that you get to learn lab technique, which if your going to a research med school you should learn how to do. The tests are very often, but I thaught they were easy.
If you want real good lab technique, take chem 154. You do tons of stuff. The problem is that you have three very hard lab reports you have to do. But the class itself is quite fun.