I took it sophomore year, and it was fine. I'm taking the MCAT in April and am not having any terrible problems with remembering the stuff I learned a year ago. If you would feel more comfortable taking it as a junior, go ahead. We can't make the decision for you!
Okay this may be more suited for the MCAT forum but screw it. Does the MCAT physics section have more Physics I than II? Because honestly I am getting a backside SN2 attack by Physics II right now (don't flame me for my horrible Organic Chemistry joke!!!).
That's a great ochem joke, i always giggled when the prof said backside attack. Too bad the rest of my class was a bunch of humorless ninnies. Anyhoo, I took the MCAT last August without Physics II and there were almost no electromagnetism/optics/etc... on it. The only electric charge problem was pretty simple. IMO, you can get by if you just review some of the physics material in the comprehensive review books.
I agree that reviewing/learning the physics material from the review books is doable. However, I seem to remember a couple of electromagnetism problems, a waves passage, and an optics passage on my MCAT, so don't ignore Physics II stuff.