Tbh I see where you're coming from. For me personally it's the opposite, the first half of Stairway to Heaven is the more forgettable part. Don't get me wrong, it's still good, but it's too calm for my taste and the drums don't even kick in until the 4 minute mark. That guitar solo, though, is one of the absolute best I have ever heard. It is comparable to the solo in Comfortably Numb by Pink Floyd and Octavarium by Dream Theater. And the part that follows it is just pure peak. That's just my opinion though