My favorite thing about "Stairway" has always been the tempo change later in the song. There is another band that I love that used this same sped up tempo on the outro of one of their songs.
I always tell people that this band is very much like Zeppelin in the sonic sense. Same kind of atmosphere in their music. Their guitar player and drummer in particular are two of my favorite musicians.
I'll let you compare the two songs and see if you agree with me.
"Stairway to Heaven"https://www.youtube.com/watch?v=xbhCPt6PZIU
Also, check out the 12 string Gibson Firebird that Perry is playing. They are very rare. I think that they only made them for two years, '67 and '68.