As the SiSoft2007 processor test indicates, here the extra 270MHz frequency boost does help the Core 2 Duo processor quite a bit. The performance margins are similar to those seen in MemTach.
Each time we stepped up a model the performance in both the SiSoft2007 processor and multimedia tests jumped by roughly 12%. Despite featuring just half the cache, the E6300 and E6400 do not seem to suffer because of it. Clearly these tests and applications do not fully utilize the large 4MB L2 Cache.