Yes, they are good. The difference in old and new test is largely imaginary in my opinion. I don't claimed they haven't changed, but it is a minor difference. I've been studying from very early (1-7), mid (20ish-33) and the latest (39, 40, and 41, 42 tomorrow and Saturday), I think they are all very similar, with LG having the most significant change over time (not much, but some).
That being said... why not try the later tests? They're all available; you should get newer tests, all things being equal.