As you go up in gauge of string I find that you get less harmonic overtones and more of the fundamental note.
That is why blues players seem to love fat strings and why it suits stoner rock etc
Skinnier strings tend to get a higher amount of higher harmonics in the sound and this seems to give them more sizzle and maybe accounted for a little of that wasp in a jam-jar tone that some of the 80s waddlers using .007 and .008 gauge strings along with their choice of pedals amps and settings.
Eb tuning was almost the staple tuning of half the rock and metal bands in the 70s and 80s it seemed
It was also the reason that 99% of music notation, chord songbooks and some early tab books (prior to about 1986) were all wrong and even the artist who played the tune in the first place wouldn't be able to play the song from the songbook
On that note I found this
http://youtu.be/-KR7txrLvuY