Cary,
Both of mine are together. I think you're mistaking me for Dave.
As far as the difference in sound, the Europa has a Q switch, low pass filter, and treble/bass boost/cut switches. The Essence has volume, blend, and filter. I do not find the Essence overly bright. The Europa is a bit more versatile due to its electronics package - I can go very bright with the Q switch engaged, or cut freqs when required with the boost/cut switches.
I think you'll find that on a neck through instrument that the construction of the neck has more to do with the tonal characteristics than the body does. All of the parts involved in reproducing the sound of the strings are located in the neck, e.g., bridge, bridge block, tailpiece, tuners, nut, etc. My advice is to worry less about the core and more about the neck. Now, in a set or bolt on neck, more of the tone comes from the body from what I understand. If anyone knows better feel free to pipe in as I am surely not an expert on this.
A lot of the tone comes from one's fingers as well. Don't believe me? Give your bass to someone else to play and see how it sounds. I've done that a few times and these individuals coax sounds out of them that I never could. Same goes for the Essence. It just sounded so ... right.
You would do well with either bass. I really like the small body on the Essence and the simplicity of the controls. Like you, I grew up playing Jazz basses (and Ricks) so I'm a bit put off by the larger necks you find on some of the other Alembic models (although the fine people in Santa Rosa will make you anything you want when ordering a custom from them). I find that the Europa and Essence fit what I like. The Essence is especially comfortable to me.
Hope this helps,
Alan