Some of you guys sound like some incredibly narrow minded fuckheads...
Here are the reasons I like my 8 string:
1. 27" baritone scale. I know you can get 6 string baritones, but many 8 strings come at 27"... I find it really comfortable, I enjoy the slightly sharper/brighter tone, and intonation is much better across all strings. If I ever got another 6 or 7 string I'd probably want the scale to be at least 26.5"...
2. The clean tones are beautiful. Some of the EMG equipped 6 and 7 strings I've had in the past sounded great for distorted riffing but terrible clean... The 27" scale + the pretty warm sounding/kinda low output (compared to other emgs) 808s give a nice balance of clarity and warmth for clean tones...
3. Resonance. The larger body, larger bridge, and wider neck seem to add sustain and resonance.
4. Tuning stability. I do like using floating tremolos, and used them on 6 and 7 strings, but dealing with setting them up is definitely annoying. My RG2228 has probably the most stable tuning of any guitar I've owned. Double locking fixed bridge with fine tuners = awesomely stable for recording.
5. And last but not least,the 8 string includes a 6 string AND a 7 string right there on the same guitar! You don't always have to play the 8th string, but I think having it available is cool. I can play Meshuggah-like rhythms on the low strings, Loomis/Becker/Malmsteen style shred on the high strings, and nice sounding crystal clean jazz chords in the same song using the same guitar.
I admit it's a challenge getting anything below F# or F to sound clear while keeping it playable, but I like challenges.