I haven’t been on in a long time but the Alembic Club was a great forum. Loads of information. The “Factory to Customer” build threads on the Alembic site are wonderful too.
For what it’s worth the typical Alembic neck shape - although if going custom you can have anything and some models do have what they call the ‘taper’ neck profile, in addition to the necks on the cheaper models generally being a bit chunkier - is not far removed from being Rickenbackerish, I.e. it’s pretty parallel and narrow all the way along. My custom came with by far the best factory setup I’ve ever had, and noticeably better than any other boutique I’ve had. My friend who owns my Wal Custom was very impressed at the setup.
Sound-wise they tend to be very pure and clean (some would maybe think too much so), but obviously you can change that with amps/pedals. Most, but not all of the models have filters, not bass/treble etc, although some do (e.g. Rogue, which also has the taper neck). The Series electronics are a step above everything else IMO, but you pay for them. I’d go to Alembic.com for more info as it’s a bit of a wormhole. Alembic will pretty much build you anything within the various shapes, and sometimes beyond those.