I have four mics tha I use for recording electric guitar: SM57, Sennheiser e609, Audix D2, and Cascade Fat Head II. Depends on the sound I am going for.
Ironically, I have had much better results using the so called tom mic (D2) for electric guitar (it thickens guitar nicely) and the so called guitar mic (609) on snare drum!
The 906 is a wonderful mic, but as said above, not really different from the 57 aside from that slight boost in the upper mids.
I love using the Fat Head, it gives a huge guitar sound, but requires a lot of work when mixing due to its low frequency girth and massive proximity effect, which all ribbon mics have. Tracked with the SSL and adding the Helios channel strip when mixng, though, gives a great classic guitar tone.