This question of "worth" of the i5 vs the i7 comes up every time there's a new generation. And the answer is the same. "Worth" is relative to YOU. To some people, it is not "worth" it. Whether it is "worth" it to you depends on whether
1. You want the fastest model available. Because the i7 IS faster than the i5. Yes, a little. But faster nonetheless.
2. You can afford the price difference.
To some people, paying the extra $ to have the fastest model available is not "worth" it. Their idea of "worth" might be different than yours or mine. To me, it is absolutely "worth it". Every. Single. Penny. Because I want the best possible performance and I don't want to leave anything on the table. So I will pay the extra few dollars and get the little extra "oomph". 5%. 7%. Whatever.
The other arguments against the i7 are the battery drain and the temperatures. This has been beaten to death. No, Apple will not design and sell a machine that melts. But the i7 will consume a "little" more battery than the i5, because, of course, it is faster, so it needs more juice. This should also play into your calculation. If you want that extra % of battery life, although it might not be much, then choose the i5.
Whether it is "worth" it is something only YOU can answer since the concept of worth is relative to your own situation. If you are asking ME whether I think it is worth it, then yes. Absolutely. To me it is.