I can't comment on the SB's isolation compared to the Eterna (never owned it). Etys are famed for their isolation & most every universal IEM will pale in comparison. The SB sounds best with a shallow in-ear fit, so that doesn't help with isolation either. Bottom line: if isolation is a big priority, the SB won't fit the bill.
It's funny.. the SB was one of the first phones I owned since joining HF.. since then I've owned or listened a ton of universals (including most all the budget 'titans'.. GR07, DBA-02, W4, EX600, FXT90, etc.).. the SB outlasted them all. Even moving onto customs & buying the top-tier HE-500, I'm still unable to part with the SB. Its sound is just too unique & addictive. The UM Miracle might be the phone whose soundstage finally lets me part with the SB... but we'll see.
When I get ready to sell a pair of phones, I typically listen to them while typing up the FS classified. I've tried to 'sell' the SB three or four times: by the time I get ready to hit "post," I can't bring myself to do it.. LOL. Even if I don't listen to them as often as I'd like to, they're pretty damn cool to look at!
*sigh*
Edited by FlySweep - 2/28/12 at 1:38pm