It looks nice to me on the most current versions of Firefox, IE and Safari on an XP platform. I've only looked at it on my laptop at 1680x1050, but it doesn't seem there would be any need to look at it on larger screens as it all fits quite well in this space. That said, there are two things that stand out to me as missing.
First, Alembic has always described their necks and string spacing based upon neck width at nut and 24th fret. Many others in the industry talk about string spacing at the bridge, including most bassists on at least one internet forum. I really wish Alembic would publish these numbers as a part of the instrument description.
Second, there doesn't appear to be any link to options for the instrument. That seems like it has to be on the page somewhere prominent. A link to the configurator with the correct model plugged in would be a nice touch, but I've always wished there was a bit more description of some of the options.
While not what I would consider missing, it might also be nice to link to a few pics of whole custom basses, or at least any FC Essences that may exist. Completed and fully specified instruments might provide some nice ideas for buyers who would otherwise skip an option that they would later regret.
In terms of design, the page gets awfully long if you narrow your browser window. I might set a minimum width so that you don't end up with more than three rows of examples, four at the most. I might set up a separate page with the extra samples rather than presenting quite so many right there up front. I do think it's really cool that you're using actual bass pics for the examples rather than mock-ups. Current screen resolution stats say that at least 93% of users are at 1024x768 or larger with almost no one below 800x600. Maybe this doesn't matter as most people won't scrunch their browser width so much if they don't have to, but the specs can work their way pretty far down the page. Maybe some navigation above the fold in the form of tags to the examples and specs might be in order?
Also, I understand that almost everyone will display an item for sale with a few options on it, but I would prefer that large primary pic to be at least the stock woods and configuration rather than something with over $1000 in upgrades on it. That's just personal preference - it always bothers me a little when a car dealer runs an ad for a $20K vehicle and then small prints a price as shown of $10K higher.
