I am currently a junior and intend to study physics in graduate school. At my university, solid state physics, nuclear & particle physics and statistical & thermal physics aren't taken until senior year. Nuclear & particle physics and statistical & thermal physics are offered in the fall of senior year. I am wondering whether it is worth waiting to take the physics GRE until senior year or whether I should take it this coming April. I don't plan on having to take it more than once, but taking in April seems to give me a better option if I need to. Would having a few weeks of those other classes be useful or would self-study and lots of practice this coming semester be enough? Any tips/advice is appreciated.