| The Eminence bass is an incredible substitute for the upright acoustic. Its pros and cons and balanced perfectly with its acoustic counterpart, so that if you have both then you're smiling on both sides of the fence/coin.
It's portable, can be used for airline travel (the removeable neck version, anyways), looks cool, and has a killer amplified sound. I would even go further and say that if you are relying on a bridge pickup for your amplified sound on your acoustic upright, then the Eminence trumps that.
Honestly, what's the point of lugging your doghouse to the gig? If you rely on an amp sound, that is your acoustic sound does not figure prominently in the overall scheme (for example, you play in a loud band or you like to hear yourself) then bringing an acoustic upright is really only for looks.
As I said, it's a good substitute. I am not getting rid of my Kay; in fact I look forward to getting a carved top one day. A peer of mine refered to them as "pretend" basses; I say if you want the "real" thing, then conditions must be present to allow them to be real: appropiate volume levels to hear it acoustically, a microphone to be able to project it to the crowd, enough space to play comfortably (pizz and arco) and to put down comfortably (no tripping or straddling the bass), appropiate atmospheric conditions (no freezing temperature to crack your bass--well, other people's anyways, no precipitation, no humidity above 70%).
As an upright acoustic player you often get dealt a bum hand; I'm suggesting that with the Eminence you can turn things more to your favour, especially without having to turn away from an "acoustic" sound.
One thing more: it isn't a EUB, but it can only work as an EUB. | 
