In my opinion, the difficulty between old PTs and newer PTs is miniscule, if even existent. It just goes to show how consistent LSAC is in making these tests. Your opinion may vary though, so, you should check out both.
Sure, the newer ones have a comparative reading section, but I actually found those easier than some of the passages on the older PTs.
I heard the newer PTs had more curve-breaker questions, but I don't know that for sure. My scores decreased when I skipped around from PT 50s to 60s to 70s. It probably depends on your skillset, though.
I agree that the difference in level of difficulty is very small. I think if you have a lot of time to do PTs (if you're taking in June or later) it's probably best to leave the more recent ones for closer to the test. If you're taking in Feb, then you should ignore 40s and focus on 50s/60s/70s.
Comments
Sure, the newer ones have a comparative reading section, but I actually found those easier than some of the passages on the older PTs.